I need a program to get 100 numbers between 0-20 and count the repition of the most repeated number.
Here is what I got for less amount for input (10 instead of 100) but ofc it's wrong.
#include <iostream>
using namespace std;
int main() {
int num, x,c;
for(int i=1; i<=10; i++) {
cin >> num;
if(num==x)
c++;
else
x=num;
}
cout << c;
return 0;
}
Assuming you mean the longest continuous sequence, here's one way you can do it:
#include <iostream>
int main() {
int max_val = 0, max_len = 0; // Overall longest
int cur_val = 0, cur_len = 0; // Current
for (int i = 0; i < 10; ++i) {
int val;
std::cin >> val; // read 1 number
if (val == cur_val) // if still counting the same, increment the length
++cur_len;
else { // else, set the max and reset current
if (cur_len > max_len) {
max_len = cur_len;
max_val = cur_val;
}
cur_len = 1;
cur_val = val;
}
}
// consider the very last sequence
if (cur_len > max_len) {
max_len = cur_len;
max_val = cur_val;
}
// Result
std::cout << "Longest seq: " << max_val << ", length: " << max_len << '\n';
}
Related
suppose the array is a[]={123,34533,21123}.How do i calculate the length of element at index 1?I know i am doing it all wrong but i dont know how to approach this
#include<iostream>
using namespace std;
int main()
{
int a[]={123,231,23},j=0,num,last_digit,sum;
int size_of_array=sizeof(a)/4;
int pos;
cin>>pos;
num=a[pos];
for(int i=0;i<size_of_array;i++)
{
last_digit=num%10;
sum=sum+last_digit;
num=num/10;
}
cout<<sum;
}
"i want to calculate sum of the digits of the element for which i need its length "
Confusing. If you want to convert the element to a string and then take its length, you would do this:
std::cout << "Length: " << std::to_string(a[i]).size() << std::endl;
Where i is the index into array a[].
However, if you want to calculate the sum of the digits, then I suppose you are trying to do this:
int sumCell = 0;
int cellValue = a[i];
while(cellValue > 0) {
sumCell = cellValue % 10;
cellValue /= 10;
}
Sum is in the variable sumCell.
Are you looking for one of these two solutions, or another?
Just like an ordinary int
#include<iostream>
int main() {
int a[]={123,231,23};
size_t pos; // use size_t for index and size
std::cin >> pos;
int elm = a[pos];
int cnt = 1;
while ( elm /= 10) {
++cnt;
}
std::cout << cnt << std::endl;
return 0;
}
Enter the index and get the length.
#include<iostream>
using namespace std;
int main()
{
int a[] = { 123, 231, 23 }, j = 0, num, last_digit, sum = 0, count = 0;
size_t size_of_array = sizeof(a) / 4;
size_t index;
cin >> index;
num = a[index];
while (num != 0) {
last_digit = num % 10;
sum = sum + last_digit;
num = num / 10;
count = count + 1;
}
cout << sum << endl; //sum
cout << count; //number of digits
}
I have problem with recursive functions.
I have to build a recursive function which creates an array of integer values corresponding to the digits of a given number.
For example, if I input a number like 3562, it should look like :
myArray[0] = 3
myArray[1] = 5
myArray[2] = 6
myArray[3] = 2
Here is my code :
#include <iostream>
using namespace std;
int myFunction(int num, int lenOfNum);
int main(){
int number;
int lengthCount = 0;
cout <<"Input numbers" << endl;
cin >> number;
int temp = number;
for(; number != 0; number /= 10, lengthCount++);
number = temp;
cout << myFunction(number, lengthCount) << endl;
}
int myFunction(int num, int lenOfNum){
int arr[lenOfNum];
if(num > 0){
for(int i = 0; i < lenOfNum; i++){
arr[i] = num/=10;
cout << "arr[" << i + 1 << " ]= " << arr[i] << endl;
}
return myFunction(num, lenOfNum);
}
else if(num == 0){
return 0;
} else;
}
The problem with your code is that you are calling int arr[lenOfNum] in each method call, which in short creates an array with a new reference to a memory location that can store lenOfNum integers.
To solve this, we declare the array in the main method and pass it as a parameter to the function.
int main() {
// somewhere in main after reading lenOfNum
int arr[lenOfNum];
// somewhere in main after declaring an array
myFunction(arr, number, lengthCount - 1);
}
and myFunction as
void myFunction(int *arr, int num, int idx) {
if (idx < 0) return; // you've completed processing the num
else if (num == 0) {
arr[0] = 0;
return;
}
arr[idx--] = num % 10;
myFunction(arr, num / 10, idx);
}
Using vector and rest part of your example
#include <iostream>
using namespace std;
void myFunction(vector<int> &arr, int num, int lenOfNum){
if (num < 0) {
return;
}
else if (num == 0) {
return;
}
int next_idx = lenOfNum - 1;
int digit = num % 10;
arr[next_idx] = digit;
myFunction(arr, num / 10, next_idx);
}
int main(){
int number;
int lengthCount = 0;
cout <<"Input numbers" << endl;
cin >> number;
int temp = number;
for(; number != 0; number /= 10, lengthCount++);
number = temp;
auto arr = vector<int>(lengthCount, 0);
myFunction(arr, number, lengthCount);
for(int i = 0; i < arr.size(); i++){
cout << "arr[" << i << " ]= " << arr[i] << endl;
}
}
Works for positive numbers
#include <vector>
#include <stdio.h>
std::vector<int> myFunction(int num)
{
std::vector<int> ret;
int irec = num / 10;
if (irec > 0)
ret = myFunction(irec);
ret.push_back('0' + (num % 10));
return ret;
}
int main(int argc, char *argv[])
{
std::vector<int> res = myFunction(539);
for(unsigned int i = 0; i < res.size(); i++)
printf("%c,", res[i]);
}
I was making an app that calculates the mean, median, and range of any integers, but I ran into the issue: Vector subscript out of range. I've looked at some other posts about this, and still haven't been able to fix it.
Here's my code:
#include <iostream>
#include <Algorithm>
#include <Windows.h>
#include <vector>
using namespace std;
int main() {
//Variables
int sze;
int mraw = 0;
double mean;
double median;
double range;
int fullnum = 0;
int lastnum = 1;
vector<int> med;
cout << "How many numbers do you have? ";
cin >> sze;
int *arr = new int[sze];
for (int i = 0; i < sze; i++) {
med.push_back(arr[i]);
}
//Getting numbers
for (int i = 0; i < sze, i++;) {
system("cls");
cout << "Enter number #" << i + 1 << ": ";
cin >> arr[i];
}
//Mean
for (int i = 0; i < sze; i++){
fullnum += arr[i];
}
mean = fullnum / sze;
//Median
sort(med.begin(), med.end());
int mvs = sze;
while (med.size() >= 2) {
med.erase(med.begin());
med.erase(med.begin() + med.size() - 1);
mvs--;
}
if (mvs == 2) {
mraw = med[1] + med[2];
median = mraw / 2;
}
else {
median = mvs;
}
//Range
vector<int> rnge;
for (int i = 0; i < sze; i++) {
rnge.push_back(arr[i]);
lastnum++;
}
sort(rnge.begin(), rnge.end());
int bigsmall[2];
bigsmall[1] = rnge[1];
bigsmall[2] = rnge[lastnum];
range = bigsmall[2] - bigsmall[1];
//Outputs
cout << "Mean: " << mean << "\nMedian: " << median << "\nRange: " << range;
system("cls");
return 0;
}
You have what would be an off-by-one error if lastnum was initialized to 0.
When rnge is empty, presumably lastnum is 0. This means access rnge[lastnum] is in error, as rnge is empty.
Applying an inductive argument shows that lastnum is the count of number of elements, and not the index of the last element. Thus, rnge[lastnum] is always out of range.
In actuality, you have initialized lastnum to 1, so your bug is actually off-by-two.
I am trying to write a code that takes a binary number input as a string and will only accept 1's or 0's if not there should be an error message displayed. Then it should go through a loop digit by digit to convert the binary number as a string to decimal. I cant seem to get it right I have the fact that it will only accept 1's or 0's correct. But then when it gets into the calculations something messes up and I cant seem to get it correct. Currently this is the closest I believe I have to getting it working. could anyone give me a hint or help me with what i am doing wrong?
#include <iostream>
#include <string>
using namespace std;
string a;
int input();
int main()
{
input();
int decimal, x= 0, length, total = 0;
length = a.length();
// atempting to make it put the digits through a formula backwords.
for (int i = length; i >= 0; i--)
{
// Trying to make it only add the 2^x if the number is 1
if (a[i] = '1')
{
//should make total equal to the old total plus 2^x if a[i] = 1
total = total + pow(x,2);
}
//trying to let the power start at 0 and go up each run of the loop
x++;
}
cout << endl << total;
int stop;
cin >> stop;
return 0;
}
int input()
{
int x, x2, count, repeat = 0;
while (repeat == 0)
{
cout << "Enter a string representing a binary number => ";
cin >> a;
count = a.length();
for (x = 0; x < count; x++)
{
if (a[x] != '0' && a[x] != '1')
{
cout << a << " is not a string representing a binary number>" << endl;
repeat = 0;
break;
}
else
repeat = 1;
}
}
return 0;
}
I don't think that pow suits for integer calculation. In this case, you can use shift operator.
a[i] = '1' sets the value of a[i] to '1' and return '1', which is always true.
You shouldn't access a[length], which should be meaningless.
fixed code:
int main()
{
input();
int decimal, x= 0, length, total = 0;
length = a.length();
// atempting to make it put the digits through a formula backwords.
for (int i = length - 1; i >= 0; i--)
{
// Trying to make it only add the 2^x if the number is 1
if (a[i] == '1')
{
//should make total equal to the old total plus 2^x if a[i] = 1
total = total + (1 << x);
}
//trying to let the power start at 0 and go up each run of the loop
x++;
}
cout << endl << total;
int stop;
cin >> stop;
return 0;
}
I would use this approach...
#include <iostream>
using namespace std;
int main()
{
string str{ "10110011" }; // max length can be sizeof(int) X 8
int dec = 0, mask = 1;
for (int i = str.length() - 1; i >= 0; i--) {
if (str[i] == '1') {
dec |= mask;
}
mask <<= 1;
}
cout << "Decimal number is: " << dec;
// system("pause");
return 0;
}
Works for binary strings up to 32 bits. Swap out integer for long to get 64 bits.
#include <iostream>
#include <stdio.h>
#include <string>
using namespace std;
string getBinaryString(int value, unsigned int length, bool reverse) {
string output = string(length, '0');
if (!reverse) {
for (unsigned int i = 0; i < length; i++) {
if ((value & (1 << i)) != 0) {
output[i] = '1';
}
}
}
else {
for (unsigned int i = 0; i < length; i++) {
if ((value & (1 << (length - i - 1))) != 0) {
output[i] = '1';
}
}
}
return output;
}
unsigned long getInteger(const string& input, size_t lsbindex, size_t msbindex) {
unsigned long val = 0;
unsigned int offset = 0;
if (lsbindex > msbindex) {
size_t length = lsbindex - msbindex;
for (size_t i = msbindex; i <= lsbindex; i++, offset++) {
if (input[i] == '1') {
val |= (1 << (length - offset));
}
}
}
else { //lsbindex < msbindex
for (size_t i = lsbindex; i <= msbindex; i++, offset++) {
if (input[i] == '1') {
val |= (1 << offset);
}
}
}
return val;
}
int main() {
int value = 23;
cout << value << ": " << getBinaryString(value, 5, false) << endl;
string str = "01011";
cout << str << ": " << getInteger(str, 1, 3) << endl;
}
I see multiple misstages in your code.
Your for-loop should start at i = length - 1 instead of i = length.
a[i] = '1' sets a[i] to '1' and does not compare it.
pow(x,2) means and not . pow is also not designed for integer operations. Use 2*2*... or 1<<e instead.
Also there are shorter ways to achieve it. Here is a example how I would do it:
std::size_t fromBinaryString(const std::string &str)
{
std::size_t result = 0;
for (std::size_t i = 0; i < str.size(); ++i)
{
// '0' - '0' == 0 and '1' - '0' == 1.
// If you don't want to assume that, you can use if or switch
result = (result << 1) + str[i] - '0';
}
return result;
}
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);
}