As you can see from the title I need to decrypt the strings in a text file. I have major problems with this so if you can help me I would really appreciate it.
First of all, here is the input file:
saoreecessinntfi
pmrrj ie2
borj
I want to decrypt these words like this:
sesnaestocifreni
primjer 2
broj
I have used the matrix 4x4 to do this, and here is the code so far:
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main()
{
ifstream test;
test.open("test.txt");
char word[5][5];
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
test >> word[i][j];
}
}
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
cout << word[j][i];
}
}
return 0;
}
Here is the output:
sesnaestocifreni
It only outputs the first word in text file. I think the problem with this is that I do not know how "long" is "i" and "j" in those other words beacuse the first word has 16 charachters so the counter "i" and "j" are set on 4. How to count each words charachters and if they are the same then decrpyt the word. Also if the word is right spelled I need to cout in the program "ERROR". For example
apple
I do not need to decrypt this word, beacuse it is right word, and "i" and "j" would not be the same or I do not know what I am talking about.
I think this should work just the fine for your case:
#include <cmath>
#include <fstream>
#include <iostream>
#include <string>
int matrixSize(std::string &str) {
auto x = sqrt(str.length());
return x - floor(x) == 0 ? x : 0;
}
int main() {
std::fstream file("test.txt");
std::string str;
while (std::getline(file, str)) {
if (int n = matrixSize(str)) {
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
std::cout << str.at(j * n + i);
std::cout << std::endl;
} else
std::cout << "ERROR" << std::endl;
}
return 0;
}
Sample test.txt file:
saoreecessinntfi
pmrrj ie2
borj
apple
Output on test run:
sesnaestocifreni
primjer 2
broj
ERROR
If I understand your problem correctly, you are given a line of n*n characters and need to unscramble it as given.
while (true) {
std::string line;
std::getline(cin, line);
if (line.empty())
break;
int n = 1;
while (n*n < line.size()) {
n++;
}
if (n*n != line.size()) {
std::cout << "ERROR" << std::endl;
continue;
}
std::string unscrambled;
for (int col = 0; col < n; col++)
for (int row = 0; row < n; row++)
unscrambled.append(1, line[row * n + col]);
std::cout << unscrambled << std::endl;
}
Related
#include <iostream>
#include <string>
#include <vector>
using namespace std;
string compression(const string & str){
int i = str.size();
string letters;
letters[0] = str[0];
for (int j = 0; j < i; ++j){
int count = 1;
while (str[j] == str[j+1]){
count++;
j++;
}
letters.push_back('0' + count);
letters.push_back(str[j]);
}
return letters;
}
int main(){
string input;
char c;
try {
cout << "Enter the data to be compressesed: "<< endl;
cin >> input;
for (int z = 0; z < input.length(); ++z){
c = input.at(z);
}
if (!(c >= 'a' && c <= 'z')){
throw runtime_error("error: invalid input");
}
}
catch (runtime_error& excpt){
cout << excpt.what() <<endl;
return 0;
}
cout << "The compressed data is " << compression(input) << endl;
return 0;
}
The expected output is , repeated for each run of characters. Here is the amount of times is repeated in sequence.
Some examples:
aaeeeeae = 2a4e1a1e
rr44errre = invalid input
eeeeeeeeeeeeeeeeeeeee = 21e
the code works properly only if the character is repeated consecutively 9 times or less. for values of 10 and more the input is other symbols.
For example it stays blank for 10, so if input is 'aaaaaaaaaabb',output just would be 'a2b' instead of '10a2b'. For 11 its outputs ';',
so if input is 'aaaaaaaaaaabb', output is ';a2b' for some reason.
So my question is, how do i make the pushback work for all numbers and not just from 0-9?
Thank you for your time if u've gotten to here. ^^
If you can use c++11 or newer your function compression could look like:
string compression(const string & str){
int i = str.size();
string letters;
for (int j = 0; j < i; ++j){
int count = 1;
while (str[j] == str[j+1]){
count++;
j++;
}
letters += std::to_string(count);
letters.push_back(str[j]);
}
return letters;
}
I have coded this program and it works fine. I get the result I want but because we are using an old system to submit it, my code is rejected because it saying that the 3 last lines generate a blank of my code. Can someone please tell me where is the problem and how I can fix it? Thank you!
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
int i, row_nr;
cin >> row_nr;
if(row_nr > 1 && row_nr <= 30)
for(i = 1; i <= row_nr; i++)
{
for(int j = 0; j < row_nr; j++)
{
cout << i + j * (row_nr);
{
cout << " ";
}
}
cout << endl;
}
return 0;
}
You're outputting a space after every value, so there is going to be a space at the end of each line. You should add a check so that you don't output a space after the last value of each line. It seems like you might have intended to do this, but forgot to write the if statement.
#include <iostream>
//#include <iomanip> why?
using namespace std;
int main()
{
int row_nr;
cin >> row_nr;
if(row_nr > 1 && row_nr <= 30)
for(int i = 1; i <= row_nr; i++) //declare iterator variable in for loop statement
{
for(int j = 0; j < row_nr; j++)
{
cout << i + j * (row_nr);
if(j < row_nr - 1) //you forgot this line
{
cout << " ";
}
}
cout << '\n'; //endl flushes the buffer, unnecessary here
}
return 0;
}
I am trying to make a C++ program of the FourSum problem i.e. Does there exist a sum of four different numbers that sum to zero.
"i + j + k + l = 0" "-2 + -1 + 3 + 0 = 0"
I can get it to work, but the running time is around 10-15 times slower than the java implementation (both are naive approaches, so basically just four for loops). I know it is possible to use BinarySearch for the last loop, provided you sort the array. But it was my understanding that generally C++ should perform better and run faster than Java and certainly also Python. So how do I do that?
Any or all suggestions are welcome. Thanks.
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
using namespace std;
int main () {
string line;
int N;
ifstream myfile ("ints/ints-400-1.txt");
getline(myfile,line);
stringstream into(line);
into >> N;
std::vector<long long> vals (N);
if (myfile.is_open())
{
int i = 0;
while ( getline(myfile,line) ) {
vals[i] = stoll( line );
++i;
}
myfile.close();
}
else cout << "Unable to open file";
for (int i = 0; i != vals.size(); i++) {
for (int j = i + 1; j != vals.size(); j++) {
for (int k = j + 1; k != vals.size(); k++) {
for (int l = k + 1; l != vals.size(); l++) {
if (vals[i] + vals[j] + vals[k] +vals[l] == 0) {
cout << "true";
}
}
}
}
}
return 0;
}
EDIT: solved! I was treating negative numbers test case as 0, instead of having the output be negative as well. thanks for the help!
Here is the challenge description: https://www.codeeval.com/open_challenges/17/
I keep getting a partially solved score. I want to know why. As in my eyes, this code works. And I believe that it is O(N) time. Thanks for looking!
Here is my code:
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <vector>
#include <string>
#include <sstream>
using namespace std;
int max(int a, int b)
{
if (a > b)
return a;
else return b;
}
int maxSubArray(vector<int> values)
{
int max_so_far = values[0];
int curr_max = values[0];
for(int i = 1; i < values.size(); ++i)
{
curr_max = max(values[i], curr_max + values[i]);
max_so_far = max(max_so_far, curr_max);
}
return max_so_far;
}
int main(int argc, char *argv[])
{
std::vector<vector<int> > Values; //to hold the values of the stock price change
ifstream file(argv[1]);
std::string line; //for the txt file input
int value = 0; //for holding the value of stock change
while (std::getline(file, line))
{
int pos = 0;
if(line.length() == 0)
continue;
else
{
std::istringstream iss(line);
std::vector<int> list; // temporary list of values to be pushed back into the 2-d vector
while (iss >> value)
{
list.push_back(value);
}
Values.push_back(list);
}
}
for(int i = 0; i < Values.size(); ++i)
{
cout << maxSubArray(Values[i]);
cout << endl;
}
/*
cout << " Printing the values : " << endl;
for (int j = 0; j < Values.size(); ++j)
{
for (int k = 0; k < Values[j].size(); ++k)
cout << Values[j][k] << " ";
cout << endl;
}
*/
return 0;
}
so I swapped out some code now. I get better score but I it's still a partial.
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <vector>
using namespace std;
int max(int a, int b)
{
if (a > b)
return a;
else return b;
}
int maxSubArray(vector<int> values)
{
int max_so_far = values[0];
int curr_max = values[0];
if (curr_max < 0)
{
curr_max = 0;
max_so_far = 0;
}
for(int i = 1; i < values.size(); ++i)
{
curr_max = max(values[i], curr_max + values[i]);
curr_max = max(curr_max, 0);
max_so_far = max(max_so_far, curr_max);
}
return max_so_far;
}
int main(int argc, char *argv[])
{
std::vector<vector<int> > Values; //to hold the values of the stock price change
ifstream file(argv[1]);
std::string line; //for the txt file input
std::string token; //for the subtring that will be converted from char to int
int value = 0; //for holding the value of stock change
int count = 0;// for holding how many total cases
while (!file.eof())
{
int pos = 0;
getline(file, line);
if(line.length() == 0)
continue;
else
{
std::vector<int> list; // temporary list of values to be pushed back into the 2-d vector
while ((pos = line.find(",")) != std::string::npos )
{
token = line.substr(0,pos);
value = atoi(token.c_str());
line.erase(0, pos + 1);
list.push_back(value);
}
value = atoi(line.c_str());
list.push_back(value);
Values.push_back(list);
++count;
}
}
for(int i = 0; i < Values.size(); ++i)
{
cout << maxSubArray(Values[i]);
cout << endl;
}
cout << " Printing the values : " << endl;
for (int j = 0; j < Values.size(); ++j)
{
for (int k = 0; k < Values[j].size(); ++k)
cout << Values[j][k] << " ";
cout << endl;
}
return 0;
}
Why are you passing the vector by value here?
int maxSubArray(vector<int> values)
That looks like a significant optimization opportunity.
I think you don't read the problem exactly right. When they say 'all contiguous sub ararys', they mean you have to take the max over all i andj of for(idx = i; i < j; ++i) { total += vec[idx]; }. Right now your code basically assumes i = 0 which isn't what you are supposed to do.
Just from looking at the output examples they provide, I can see that your code isn't going to give the answer that they expect.
it seems right, the only thing I can think of is that when the list gets long, your result can overflow, so change int to long long.
Besides technical optimizations suggested in other answers, concerning the algorithm, i think a little fix can make your algorithm work. When curr_max drops to a negative value, due to encountering a negative integer that exceeds curr_max, you can simply drop all the previous integers including the current value and start over. This fix is simple, you can add one line to your loop like this:
for(int i = 1; i < values.size(); ++i)
{
curr_max = max(values[i], curr_max + values[i]);
curr_max = max(curr_max, 0); // <---------------- add this line
max_so_far = max(max_so_far, curr_max);
}
Hey so I am trying to write a simple program that adds spaces to a given string that has none in C++ here is the code I have written:
#include <iostream>
#include <string>
using namespace std;
string AddSpaceToString (string input)
{
const int arrLength = 5;
int lastFind = 0;
string output;
string dictionary[arrLength] = {"hello", "hey", "whats", "up", "man"};
for (int i = 0; i < input.length(); i++)
{
for (int j = 0; j < arrLength; j++)
{
if(dictionary[j] == input.substr(lastFind, i))
{
lastFind = i;
output += dictionary[j] + " ";
}
}
}
return output;
}
int main ()
{
cout << AddSpaceToString("heywhatshelloman") << endl;
return 0;
}
For some reason the output only gives hey whats and then stops. What is going on I can't seem to make this very simple code work.
After reading "hey" and "whats", the value of i is more than the length of "hello" and hence no such substring exists for the code input.substr(lastFind, i).
You should check for the length of possible substring (dictionary[j]) and not i.
input.substr( lastFind, dictionary[j].size() )
Also you will have to change:
lastFind += dictionary[j].size();
So the if loop becomes:
if(dictionary[j] == input.substr(lastFind, dictionary[j].size() ))
{
lastFind += dictionary[j].size();
output += dictionary[j] + " ";
}
this works
#include <iostream>
#include <string>
using namespace std;
string AddSpaceToString (string input)
{
const int arrLength = 5;
unsigned int lastFind = 0;
string output;
string dictionary[arrLength] = {"hello", "hey", "whats", "up", "man"};
for (int j = 0; lastFind < input.size() && j < arrLength; ++j)
{
if(dictionary[j] == input.substr(lastFind, dictionary[j].size()))
{
lastFind += dictionary[j].size();
output += dictionary[j] + " ";
j = -1;
}
}
return output;
}
int main ()
{
cout << AddSpaceToString("heywhatshelloman") << endl;
return 0;
}