There are five types of bit encoding: 11, 10, 01, 001, 000.The corresponding message for each bit encoding is
11 -> A
10 -> B
01 -> C
001 -> D
000 -> E
The compile result will look like this：
Enter a sequence of bits: 01100001100110
CBEADB
I've wrote this but it can't work.
#include<iostream>
#include<string>
using namespace std;
int main()
{
int A, B, C, D, E ;
string code;
cout << "Enter a sequence of bits: ";
cin >> code;
int i = 0;
while (i < code.length())
{
if( code[i]== 1 && code[i + 1]== 1 )
{
cout << 'A';
i += 2;
}
else if ( code[i]== 1 && code[i + 1]== 0)
{
cout << 'B';
i += 2;
}
else if ( code[i]== 0 && code[i + 1]== 1)
{
cout << 'C';
i += 2;
}
else if ( code[i]== 0 && code[i + 1]== 0 && code[ i + 2]== 1)
{
cout << 'D';
i += 3;
}
else if ( code[i]== 0 && code[i + 1]== 0 && code[ i + 2]== 0)
{
cout << 'E';
i += 3;
}
}
cout << endl;
return 0;
}
Your input is a String not numbers, therefore you have to check for characters. Instead of using something like == 0, you should be using something like == '0'. Also, you may want to make sure that the input has the right format and you don't run into an infinite loop (by running the while forever without updating i) or buffer overflow (aka. index out of range, by checking code[i] with i >= code.length()). You can do something like:
#include<iostream>
#include<string>
using namespace std;
int main()
{
int A, B, C, D, E ;
string code;
cout << "Enter a sequence of bits: ";
cin >> code;
int i = 0;
while (i+1 < code.length())
{
if( code[i]== '1' && code[i + 1]== '1' )
{
cout << 'A';
i += 2;
}
else if ( code[i]== '1' && code[i + 1]== '0')
{
cout << 'B';
i += 2;
}
else if ( code[i]== '0' && code[i + 1]== '1')
{
cout << 'C';
i += 2;
}
else if (i+2 < code.length())
{
if (code[i]== '0' && code[i + 1]== '0' && code[ i + 2]== '1')
{
cout << 'D';
i += 3;
}
else if ( code[i]== '0' && code[i + 1]== '0' && code[ i + 2]== '0')
{
cout << 'E';
i += 3;
}
else
{
return 1;
}
}
else
{
return 1;
}
}
if (i < code.length()) {
return 1;
}
cout << endl;
return 0;
}
You can try it out here.
You code is correct, you simply need to use character literals instead of int literals, for example:
if (code[i] == '1' && code[i + 1] == '1')
Digits, in strings, have codes that don't match their integral value. '0' is not 0. As such, you must use '0' and '1'.
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A few time ago I made a game similar to Gomoku in C++ that is taking between two players.
Now I want to make it Player vs Computer.
I tried to do it in simplest way, by making a function of computer to pick a random cell but I still haven't succeeded.
I understood that in order of getting a random number I can use rand() and for a letter something like this:
char letters[] = "abcdefghijklmnopqrstuvwxyz";
char x = letters[rand() % 26];
Can someone help me and describe how to implement a computer player?
This is my implementation so far:
#include <iostream>
#include <iomanip>
using namespace std;
void print_table(int x[][15]) {
system("cls");
for (int i = 0; i < 15; i++) {//the loop that use to print out the english character row
if (i == 0)
cout << setw(4) << "A";
else if (i == 1)
cout << " B";
else if (i == 2)
cout << " C";
else if (i == 3)
cout << " D";
else if (i == 4)
cout << " E";
else if (i == 5)
cout << " F";
else if (i == 6)
cout << " G";
else if (i == 7)
cout << " H";
else if (i == 8)
cout << " I";
else if (i == 9)
cout << " J";
else if (i == 10)
cout << " K";
else if (i == 11)
cout << " L";
else if (i == 12)
cout << " M";
else if (i == 13)
cout << " N";
else if (i == 14)
cout << " O";
else if (i == 15)
cout << " P";
}
cout << endl;
for (int i = 0; i < 15; i++) {
cout << setw(2) << i;//print out the row number
for (int j = 0; j < 15; j++) {//print out the board game.
if (x[i][j] == 0) {//the inital value is 0, so when the block is 0 then print out the '.'
cout << " .";
}
else if (x[i][j] == 1) {//when the player O input the block then the value will adding one then if check the block is one then output the 'o'
cout << " O";
}
else if (x[i][j] == 2) {//when the player X input the block then the value will adding two then if check the block is two then output the 'x'
cout << " X";
}
}
cout << endl;
}
}
int check_player(int p) {
if (p == 1) {//change the player everytime before the next loop compile
p++;
}
else {
p--;
}
return p;
}
void input_value(int &t, int &n, int p, int x[][15]) {
char eng;
int number;
do {//the loop that ask for the user input the location.
cout << "player ";
if (p == 1) {
cout << "O";
}
else {
cout << "X";
}
cout << ", make a move: ";
cin >> eng;//input the location
cin >> number;
if (eng == 'A')//change the character to different number
t = 0;
else if (eng == 'B')
t = 1;
else if (eng == 'C')
t = 2;
else if (eng == 'D')
t = 3;
else if (eng == 'E')
t = 4;
else if (eng == 'F')
t = 5;
else if (eng == 'G')
t = 6;
else if (eng == 'H')
t = 7;
else if (eng == 'I')
t = 8;
else if (eng == 'J')
t = 9;
else if (eng == 'K')
t = 10;
else if (eng == 'L')
t = 11;
else if (eng == 'M')
t = 12;
else if (eng == 'N')
t = 13;
else if (eng == 'O')
t = 14;
if (!(eng >= 'A'&&eng <= 'M') || !(number >= 0 && number <= 14) || x[number][t] != 0) {//when the input wrong, output the statement to ask anouther input and loop again.
cout << "Invaid input, Try again!" << endl;
continue;
}
else {//if no problem then this input loop is break and jump to the next statement
break;
}
} while (1);//Because it will break as well so the do-while loop is no any requirement
n = number;
}
int main() {
const int num = 15;//the number for constant the array row and column value
char check_e;//for the user input the column
int R[num][num] = { 0 }, check_n, player = 1, buger = 0, transfer, playerO_win = 0, playerX_win = 0, draw = 0, check_draw;//the variable that for user input or checking the game statment
do {//launch the loop for the user input again and again
check_draw = 0;//reset the checking of draw
print_table(R);
input_value(transfer, check_n, player, R);
R[check_n][transfer] += player;//change the value according the player's input and the player name.
for (int i = 0; i < num; i++) {
for (int j = 0; j < num; j++) {
if (i <= 8 && R[j][i] != 0 && (R[j][i] == R[j][i + 1] && R[j][i] == R[j][i + +2] && R[j][i] == R[j][i + 3] && R[j][i] == R[j][i + 4])) {//the checking for the row bingo
if (R[j][i] == 1) {
playerO_win++;
break;
}
else {
playerX_win++;
break;
}
}
else if (j <= 8 && R[j][i] != 0 && (R[j][i] == R[j + 1][i] && R[j][i] == R[j + 2][i] && R[j][i] == R[j + 3][i] && R[j][i] == R[j + 4][i])) {//the checking for the column bingo
if (R[j][i] == 1) {
playerO_win++;
break;
}
else {
playerX_win++;
break;
}
}
else if (j <= 8 && i <= 8 && R[j][i] != 0 && (R[j][i] == R[j + 1][i + 1] && R[j][i] == R[j + 2][i + 2] && R[j][i] == R[j + 3][i + 3] && R[j][i] == R[j + 4][i + 4])) {//the checking for the \ situation.
if (R[j][i] == 1) {
playerO_win++;
break;
}
else {
playerX_win++;
break;
}
}
else if ((j >= 4 || i >= 4 || i <= 8) && R[j][i] != 0 && (R[j][i] == R[j - 1][i + 1] && R[j][i] == R[j - 2][i + 2] && R[j][i] == R[j - 3][i + 3] && R[j][i] == R[j - 4][i + 4])) {//the checking for the / situation
if (R[j][i] == 1) {
playerO_win++;
break;
}
else {
playerX_win++;
break;
}
}
for (int i = 0; i < num; i++) {//the loop for checking the draw
for (int j = 0; j < num; j++) {//this loop will check for every time compilation.
if (R[j][i] == 0)//when there are any empty block then the check_draw will adding, the draw situation is the check_draw be 0
check_draw++;
}
}
if (check_draw == 0) {//when the check_draw equal to 0 which mean the situation is no empty block
draw++;
break;
}
}
if (playerO_win != 0 || playerX_win != 0 || draw == 1)//break the second loop
break;
}
if (playerO_win == 1 && playerX_win == 0) {// when the player win print the block game again and print out the win statement
print_table(R);
cout << "player O wins!" << endl;
break;
}
else if (playerX_win == 1 && playerO_win == 0) {//the other player win the game
print_table(R);
cout << "player X wins!" << endl;
break;
}
else if (draw == 1) {//the draw block game print
print_table(R);
cout << "Draw game!" << endl;
break;
}
player = check_player(player);
} while (1);//in fact it is no need for the loop statement, because most of the situation will have a break statement for out of the loop
return 0;
}
Here's how I would implement it probably based on your initial implementation:
#include <iostream>
#include <iomanip>
#include <cstdlib>
using namespace std;
#define SIZE 10
#define LINE_LENGTH 4
#define COMPUTER_O_PLAYER true
#define COMPUTER_X_PLAYER false
void print_board(unsigned char x[SIZE][SIZE]) {
cout << " ";
for (int i = 0; i < SIZE; i++) { // The loop that use to print out the english character row.
cout << (char) ('A' + i) << " ";
}
cout << endl;
for (int i = 0; i < SIZE; i++) {
cout << setw(2) << i; // Print out the row number.
for (int j = 0; j < SIZE; j++) {//print out the board game.
if (x[i][j] == 0) { // Unoccupied tile.
cout << " .";
} else if (x[i][j] == 1) { // The tile belongs to X.
cout << " X";
} else { // The tile belongs to O.
cout << " O";
}
}
cout << endl;
}
}
void get_position(int &x, int &y, bool player, unsigned char board[SIZE][SIZE]) {
char eng;
// The loop that ask for the user input the location.
do {
cout << "Player " << (player ? "X" : "O") << ", make a move: ";
cin >> eng;
y = toupper(eng) - 'A';
cin >> x;
if (!(x >= 0 && x < SIZE) || !(y >= 0 && y < SIZE) || board[x][y] != 0) {
// When the input wrong, output the statement to ask another input and loop again.
cout << "Invalid input, Try again!" << endl;
continue;
} else { // If no problem then this input loop is break and jump to the next statement.
break;
}
} while (true);
}
void get_random_position(int &x, int &y, bool player, unsigned char board[SIZE][SIZE]) {
do {
x = rand() % SIZE;
y = rand() % SIZE;
} while ((!(x >= 0 && x < SIZE) || !(y >= 0 && y < SIZE) || board[x][y] != 0));
cout << "Player " << (player ? "X" : "O") << " chose: " << (char) ('A' + y) << x << endl;
}
unsigned int
count_in_direction(unsigned char board[SIZE][SIZE], unsigned int x, unsigned int y, short int m_x, short int m_y) {
unsigned int count = 0;
unsigned char tile = board[x][y];
while (((x + m_x >= 0) && (x + m_x < SIZE)) && ((y + m_y >= 0) && (y + m_y < SIZE)) &&
(board[x + m_x][y + m_y] == tile)) {
x += m_x;
y += m_y;
count++;
}
return count;
}
bool full_line(unsigned char board[SIZE][SIZE], unsigned int x, unsigned int y) {
const short int directions[4][2] = {{1, 0},
{1, -1},
{0, 1},
{1, 1}};
for (const auto &direction : directions) {
if (LINE_LENGTH - 1 <= (count_in_direction(board, x, y, direction[0], direction[1]) +
count_in_direction(board, x, y, -direction[0], -direction[1])))
return true;
}
return false;
}
int main() {
// The variable that for user input or checking the game state.
unsigned char board[SIZE][SIZE] = {0};
int x, y;
bool player = true;
bool draw;
srand(time(nullptr));
// Run the game.
do {
print_board(board);
if ((player && COMPUTER_X_PLAYER) || (!player && COMPUTER_O_PLAYER)) {
get_random_position(x, y, player, board);
} else {
get_position(x, y, player, board);
}
board[x][y] = player ? 1 : 2;
if (full_line(board, x, y)) {
print_board(board);
cout << "player " << (player ? "X" : "O") << " wins!" << endl;
break;
}
draw = true;
for (int k = 0; (k < SIZE) && draw; k++) {
for (int l = 0; (l < SIZE) && draw; l++) {
if (board[k][l] == 0) draw = false;
}
}
if (draw) {
print_board(board);
cout << "Draw game!" << endl;
break;
}
player = !player;
} while (true);
return 0;
}
Please take a deep look in this implementation and internalize its approach, it also support both players as user, user and computer, and both computer.
Some insights:
Don't use long if ... else when there are simpler ways.
Use the correct data types for variables.
Use indicative variables naming.
Use loops where possible, again, not long if ... else.
Keep the code well formatted.
Use #define to define global constants to use, for easier changes later and readability.
You can indeed use rand, but you don't need to get a character, you can get an index straight away and avoid the conversion.
I am solving a question which states: to change every '?' with 'a' in a string if doesn't contain if won't form consecutive 'a' else substitute with 'b', eg. a?b will be abb and not aab because here 2 a's are consecutive.
My problem is for i = 3 my string should be over- written with 'b ' according to my code it is entering into the desired block but the string does n't gets written with b, but in all the other case where it should be witten with 'a' it get's written .Help me out with these.
You can refer the problem statement from here to for better understanding my problem :https://www.hackerearth.com/practice/algorithms/greedy/basics-of-greedy-algorithms/practice-problems/algorithm/exploring-ruins/
#include <iostream>
using namespace std;
int main() {
string str;
cin >> str;
int n = str.size();
for(int i = 0; i < str.size(); i++) {
if(str[i] == '?') {
if(i == 0) {
if(str[i + 1] == 'a')
str[i] = 'b';
else
str[i] = 'a';
cout << "I am in if" << endl;
} else if(i == n - 1) {
if(str[i - 1] == 'a')
str[i] == 'b';
else
str[i] == 'a';
cout << "I am in if of else if " << endl;
} else {
if(str[i + 1] == 'a' || str[i - 1] == 'a') {
str[i] == 'b';
cout << "I am in if of else " << endl;
} else {
str[i] = 'a';
cout << "I am in else of else " << endl;
}
}
cout << str[i] << endl;
} else
continue;
}
cout << str << endl;
return 0;
}
Given string : ?ba??b
desired output : ababab
my output : aba?ab
It will be a lot easier for you if you would use functions to solve this problem.
bool check_neighbors_for_a(const string &str, size_t place) {
bool result = false;
if (place > 0) { // If there is a char before the current char
result = str[place - 1] == 'a'; // If the previous char is 'a' result become true
}
if (place < str.size() - 1) { // If there is a char after the current char
result = result || str[place + 1] == 'a'; // If the result has become true before this line, result will stay true. Else, result will be true if the next char is equal to 'a'.
// For example: b?a => result = (false || 'a' == 'a')
// For example: a?b => result = (true || 'b' == 'a')
// For example: a?a => result = (true || 'a' == 'a')
}
return result;
}
void replace_questions_by_a(string &str) {
for (size_t i = 0; i < str.size(); i++) {
if (str[i] == '?') {
if (check_neighbors_for_a(str, i)) { // If one of the neighbors is equal to 'a'
str[i] = 'b'; // Place 'b' instead of '?'
} else {
str[i] = 'a'; // Place 'a' instead of '?'
}
}
}
}
I am writing a C++ program that converts between Arabic and Roman numbering systems. I wrote one program that converts Arabic to Roman and have another program that converts Roman to Arabic.
The problem is that I can't figure out how to merge them into one single program so that the user can input an Arabic or Roman number and as a result, the program would convert said number to the other.
My question is HOW can I merge these two programs into one?
Code for Roman to Arabic
#include <iostream>
using namespace std;
int main()
{
char roman_Numeral;
int arabic_Numeral = 0;
cout << "Enter the Roman Numeral in Capital letters (e.g. CCXIX) : ";
while (cin.get(roman_Numeral))
{
if (arabic_Numeral > 100)
{
cout << "\nInvalid Value. Number must be between I and C" << endl;
return 0;
}
else if (roman_Numeral == 'C')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D')
{
arabic_Numeral = arabic_Numeral - 100;
}
else
{
arabic_Numeral = arabic_Numeral + 100;
}
}
else if (roman_Numeral == 'L')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C')
{
arabic_Numeral = arabic_Numeral - 50;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 50;
continue;
}
}
else if (roman_Numeral == 'X')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L')
{
arabic_Numeral = arabic_Numeral - 10;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 10;
continue;
}
}
else if (roman_Numeral == 'V')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L'
|| roman_Numeral == 'X')
{
arabic_Numeral = arabic_Numeral - 5;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 5;
continue;
}
}
else if (roman_Numeral == 'I')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L'
|| roman_Numeral == 'X' || roman_Numeral == 'V')
{
arabic_Numeral = arabic_Numeral - 1;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 1;
continue;
}
}
else
break;
}
cout << arabic_Numeral << endl;
return 0;
}
Code for Arabic to Roman
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
#define MAX_INPUT 100 // These constants hold high and low integer numbers,
#define MIN_INPUT 1
#define ARRAY_SIZE 4 // and the array size declarator.
string convert(int digit, string low, string mid, string high);
int main()
{
string answers[ARRAY_SIZE] = { "", "", "", "" }; //An array of string to hold the output from the convert function.
int accumulator = 0; // Variable to hold number of arabic numbers converted.
int userNum = 0;
string strUserNum;
do
{
cout << "";
cout << "Enter an arabic number between 1 and 100: ";
cin >> strUserNum;
userNum = std::stoi(strUserNum);
if (userNum == 0 || userNum > MAX_INPUT)
{
cout << "\nInvalid Value. Number must be between 1 and 100" << endl;
return 0;
}
else if (userNum == 'end')
{
cout << "Exiting program:";
break;
}
int thous = userNum / 1000;
int hund = userNum % 1000 / 100;
int tens = userNum % 100 / 10;
int ones = userNum % 10 / 1;
answers[0] = convert(thous, "M", "M", "M");
answers[1] = convert(hund, "C", "D", "M");
answers[2] = convert(tens, "X", "L", "C");
answers[3] = convert(ones, "I", "V", "X");
cout << answers[0] << answers[1] << answers[2];
cout << answers[3] << endl;
cout << endl;
break;
} while (userNum != 'end');
system("PAUSE");
return 0;
}
string convert(int digit, string low, string mid, string high)
{
if (digit == 1)
{
return low;
}
if (digit == 2)
{
return low + low;
}
if (digit == 3)
{
return low + low + low;
}
if (digit == 4)
{
return low + mid;
}
if (digit == 5)
{
return mid;
}
if (digit == 6)
{
return mid + low;
}
if (digit == 7)
{
return mid + low + low;
}
if (digit == 8)
{
return mid + low + low + low;
}
if (digit == 9)
{
return low + high;
}
if (digit == 0)
{
return "";
}
}
Put code (that inside the main block) for Roman to Arabic into void procedureRomanToArabic()
The same for Roman to Arabic. Put it into void procedureArabicToRoman().
Remove remove ArabicToRoman do-while and move it to main.
void procedureRomanToArabic(){
char roman_Numeral;
int arabic_Numeral = 0;
//...
cout << arabic_Numeral << endl;
}
void procedureArabicToRoman()
{
string answers[ARRAY_SIZE] = { "", "", "", "" }; //An array of string to hold the output from the convert function.
int accumulator = 0; // Variable to hold number of arabic numbers converted.
int userNum = 0;
string strUserNum;
//remove do while here
cout << "";
cout << "Enter an arabic number between 1 and 100: ";
cin >> strUserNum;
//...
answers[2] = convert(tens, "X", "L", "C");
answers[3] = convert(ones, "I", "V", "X");
cout << answers[0] << answers[1] << answers[2];
cout << answers[3] << endl;
cout << endl;
}
int main(){
char type;
do{
cout<<"2 for Arabic to Roman, 1 for Roman to Arabic, or anything else for exit";
cin>>type;
if(type=='1')
procedureArabicToRoman();
else if(type =='2')
procedureRomanToArabic();
else break; //end program
} while(true);
}
This program is a part of an exam I just took, that I had to write. I only got this far and couldn't get anywhere. Here is the prompt:"Write a Test Function toDecimal() that converts a roman numeral such as MMLXVII to it's decimal number representation. Use Main() to test the function. The toDecimal() function should have 2 arguments, the string array of roman numerals and a helper function. This helper function will return the numeric value of each of the letters used in roman numbers. Then convert the string arguments as so: Look at the first two characters,if the first is larger, convert the first and add it to the summation, then call the conversion function again with the second value and add both. IF the first character is lesser than the second subtract the first from the second, and add the result to the conversion of the string. without validation it will also convert strings like "IC". VAlidate the string arguement, if there is an error, call the error processing function. Provide at least two error processing functions and test toDecimal() with each. One could be adking the user to correct, the other may correct it."
I,X,C,M cannot be repeated more than 3 times in succession, D,L,V, can never be repeated in succession.I can only be subtracted from V and X,X can only be subtracted from L and C, C can only be subtracted from D and M. V, L, and D can never be subtracted.
I've lost about 2 days worth of sleep on this, tried writing it hundreds of different ways using and breaking the rules. This is the closest I've got on it.
#include <iostream>
#include <string>
#include <map>
#include <algorithm>
#include <cstring>
using namespace std;
bool checker(string roman);
// Adds each value of the roman numeral together
int toDecimal(string, bool* (*function)(string));
int convert(string roman, int i);
int main(){
string roman;
cout << "This program takes a roman numeral the user enters then converts it to decimal notation." << endl;
cout << "Enter a roman numeral: ";
cin >> roman;
transform(roman.begin(), roman.end(), roman.begin(), toupper);
cout << roman << " is equal to " << toDecimal(roman, *checker(roman)) << endl;
}
bool checker(string roman){
int length = roman.length();
for (int count = 0; count < length; count++){
string sub = roman.substr(count, count);
if(sub != "I" || sub != "V" || sub != "X" || sub != "L" || sub != "C" || sub != "D" || sub != "M"){
cout << "Error. Try Again"<< endl;
return false;
}
else if(convert(roman, count) == convert(roman, count-1) && convert(roman, count) == convert(roman, count+1)){
if (convert(roman,count) == 1 || convert(roman,count) == 10 || convert(roman,count) == 100 || convert(roman,count) == 1000)
if(convert(roman, count-1) == convert(roman, count-2) || convert(roman, count+1) == convert(roman, count+2)){
cout << "Error Try again" << endl;
return false;
}
else if (convert(roman,count) == 5 || convert(roman,count) == 50 || convert(roman,count) == 500){
cout << "Error Try again" << endl;
return false;
}
else return true;
}
}
return true;
}
int toDecimal(string s, bool*(checker) (string roman)){
/**map<char, int> roman;
roman['M'] = 1000;
roman['D'] = 500;
roman['C'] = 100;
roman['L'] = 50;
roman['X'] = 10;
roman['V'] = 5;
roman['I'] = 1;*/
checker(s);
int res = 0;
for (int i = 0; i < s.length() - 1; ++i){
int num = convert(s,i);
res += num;
/**if (roman[s[i]] < roman[s[i+1]])
res -= roman[s[i]];
else
res += roman[s[i]];
}
res += roman[s[s.size()-1]];*/}
return res;
}
int convert(string roman, int i){
enum romans {I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000};
int num = 0;
char c = roman[0];
switch(c){
case 'M':
num = M; break;
case 'D':
if(i + 1 != roman.size() && roman[i+1] == 'M'){
num = M - D;break;
}
else
num = D; break;
case 'C':
if(i + 1 != roman.size() && roman[i+1] == 'M' || roman[i+1] == 'D'){
if(roman[i+1] == 'M') num = M - C; break;
if(roman[i+1] == 'D') num = D - C; break;
}
else
num = C; break;
case 'L':
if(i + 1 != roman.size() && roman[i+1] == 'M' || roman[i+1] == 'D' || roman[i+1] == 'C'){
if(roman[i+1] == 'M') num = M - L; break;
if(roman[i+1] == 'D') num = D - L; break;
if(roman[i+1] == 'C') num = C - L; break;
}
else
num = L; break;
case 'X':
if(i + 1 != roman.size() && roman[i+1] == 'M' || roman[i+1] == 'D' || roman[i+1] == 'C'|| roman[i+1] == 'L'){
if(roman[i+1] == 'M') num = M - X; break;
if(roman[i+1] == 'D') num = D - X; break;
if(roman[i+1] == 'C') num = C - X; break;
if(roman[i+1] == 'L') num = C - X; break;
}
num = X; break;
case 'V':
if(i + 1 != roman.size() && roman[i+1] == 'M' || roman[i+1] == 'D' || roman[i+1] == 'C'|| roman[i+1] == 'L' || roman[i+1] == 'X'){
if(roman[i+1] == 'M') num = M - V; break;
if(roman[i+1] == 'D') num = D - V; break;
if(roman[i+1] == 'C') num = C - V; break;
if(roman[i+1] == 'L') num = L - V; break;
if(roman[i+1] == 'X') num = X - V; break;
}
num = V; break;
case 'I':
if ( i + 1 != roman.size() && roman[i + 1] != 'I'){
if(roman[i+1] == 'M') num = M - I; break;
if(roman[i+1] == 'D') num = D - I; break;
if(roman[i+1] == 'C') num = C - I; break;
if(roman[i+1] == 'L') num = L - I; break;
if(roman[i+1] == 'X') num = X - I; break;
}
num =1; break;
}
return num;
}
** I have added the help of people on here. This is an edit to show an progress/congress.
This is the code that I use to convert Roman (smaller than 3999) to Integer. You may check if it works for larger numbers.
int romanToInt(string s) {
map<char, int> roman;
roman['M'] = 1000;
roman['D'] = 500;
roman['C'] = 100;
roman['L'] = 50;
roman['X'] = 10;
roman['V'] = 5;
roman['I'] = 1;
int res = 0;
for (int i = 0; i < s.size() - 1; ++i)
{
if (roman[s[i]] < roman[s[i+1]])
res -= roman[s[i]];
else
res += roman[s[i]];
}
res += roman[s[s.size()-1]];
return res;
}
Hope this could help you.
The solution provided by Annie Kim works, but it uses a std::map, querying it several times for the same character, and I fail to see a reason for it.
int convert_roman_digit(char d)
{
switch (d)
{
case 'M': return 1000;
case 'D': return 500;
case 'C': return 100;
case 'L': return 50;
case 'X': return 10;
case 'V': return 5;
case 'I': return 1;
default: throw std::invalid_argument("Invalid digit");
}
}
int roman_to_int(const std::string& roman)
{
int result = 0, last_added = 0;
for (auto it = roman.rbegin(); it != roman.rend(); ++it)
{
const int value = convert_roman_digit(*it);
if (value >= last_added)
{
result += value;
last_added = value;
}
else
{
result -= value;
}
}
return result;
}
Caveat: the function happily accepts some invalid inputs (e.g. IMM) including "negative" numbers (e.g. IIIIIIIIIIIIIX), there are no overflow checks, and it throws. Feel free to improve it.
int romanToInt(string s)
{
unordered_map<char, int> roman;
roman['I'] = 1;
roman['V'] = 5;
roman['X'] = 10;
roman['L'] = 50;
roman['C'] = 100;
roman['D'] = 500;
roman['M'] = 1000;
int num = 0, prev = 0, curr;
for (int i = s.length() - 1; i >= 0; i--)
{
curr = roman[s[i]];
num += (curr >= prev ? 1 : -1) * curr;
prev = curr;
}
return num;
}
For example, how do you count the occurrence of "TJ" in OAEKOTJEOTJ?
if (s[i] == 'TJ') and (s[i] == 'T'+'J')
x += 1;
First one gives me an error, second one doesn't count. I need a beginner solution to this, I haven't learned very much about c++ commands yet. Thanks
int x = 0
string s;
cin >> s;
for (int i = 0; i < 100; i++)
if (s[i] == T || s[i] == t) && (s[i+1] == J || s[i+1] == j)
x += 1
cout << x << endl;
That's the excerpt from my code, it doesn't count any tj, tJ, Tj or TJ
Try using:
if(s[i] == 'T' && s[i+1] == 'J') // and make sure you do not run out of bounds of string with index i.
x += 1;
EDIT:
Based on your code:
int x = 0
string s;
cin >> s;
for (int i = 0; i < 100; i++)
if (s[i] == T || s[i] == t) && (s[i+1] == J || s[i+1] == j)
x += 1
cout << x << endl;
You should do it like following:
int x = 0
string s;
cin >> s;
for (int i = 0; i < s.length()-1; i++) // use size of string s.length()-1 to iterate the string instead of 100
if (s[i] == 'T' || s[i] == 't') && (s[i+1] == 'J' || s[i+1] == 'j') // compare the ascii values of characters like - 'T' 'J' etc.
x += 1
cout << x << endl;
std::string provides a function find which searches the string for substrings, including multi-character substrings (below, I am using C++11 syntax):
#include <iostream>
#include <string>
int main()
{
using namespace std;
string text { "OAEKOTJEOTJ" };
unsigned int occ { 0 };
size_t pos { 0 };
for (;;) {
pos = text.find("TJ",pos); // Search for the substring, start at pos
if (pos == string::npos) // Quit if nothing found
break;
++pos; // Continue from next position
++occ; // Count the occurrence
}
std::cout << "Found " << occ << " occurrences." << std::endl;
}
The way it's done above we advance by one character only after each match. Depending on whether/how we want to deal with overlapping matches, we might want to advance pos by the length of the search pattern. (See chris's comment as well.)
Try this:
#include <locale> // for tolower() function
string tolower(string s) {
tolower(s[0]);
tolower(s[1]);
return s;
}
...
int main() {
string s;
cin >> s;
int n = s.size(),cont = 0;
for(int i = 0; i < n ; ++i) {
if(tolower(s.substr(i,2)) == "tj") {
++cont;
}
}
cout << cont << endl;
return 0;
}