程序未进入FOR循环

Question

I don't know why, but the program is not entering into the FOR loop. I am completely new to programming so Please avoid any errors if there. Help much appreciated.

This question is from one of the coding websites::

You are given a list of N people who are attending ACM-ICPC World Finals. Each of them are either well versed in a topic or they are not. Find out the maximum number of topics a 2-people team can know. And also find out how many teams can know that maximum number of topics?

Input Format

The first line contains two integers N and M separated by a single space, where N represents the number of people, and M represents the number of topics. N lines follow. Each line contains a binary string of length M. In this string, 1 indicates that the ith person knows a particular topic, and 0 indicates that the ith person does not know the topic.

Output Format

On the first line, print the maximum number of topics a 2-people team can know. On the second line, print the number of teams that can know the maximum number of topics.

Constraints

 2 ≤ N ≤ 500 1 ≤ M ≤ 500 

Sample Input

 4 5 10101 11100 11010 00101 

Sample Output

 5 2 

Here is my code ::

#include<iostream>

using namespace std;

int main(){
    int N,M;
    cin>>N>>M;

    if(N>=2 && N<=500 && M>=1 && M<=500){
        int x= (N*(N-1))/2;
        int i,j,k;
        int Topic[x];
        for(i=0;i<x;i++){
            Topic[i]=0;
        }
        int y= N*M;
        int a;
        char Array[y];
        while(N--){
            for(i=0;i<M;i++){   
                cin>>Array[a];
                a++;
            }  
          }
        int count;
        int d=0;
        int l=N-1;

        // This FOR LOOP ..

        **for(int p=0;p<l;p++){             
            for(int q=p+1;q<N;q++){
                count=0;
                for(k=0;k<M;k++){
                    int temp=k+(q*M);
                    int temp1=k+(p*M);
                    if(Array[temp]+Array[temp1]!=0){
                        count+=1;
                    }
                }
                Topic[d]=count;
                d++;
            }
        }**
        int max=Topic[0];
        int counter=0;
        for(i=0;i<x;i++){
            if(max>Topic[i]){
                 max=Topic[i];  
                 counter=1;
            }
            else if(Topic[i+1]=Topic[i]){
                counter+=1;
            }
         }

     cout<<max<<endl;
     cout<<counter;

    }

    return 0;
}

Answer 1

You have a loop that counts N down to 0 :

while (N--) {
  // ...
}

Then you set l to N - 1 , which is to say -1 :

int l = N - 1;

Then your for loop wants to run while p < l . p is initially 0 , l is initially -1 , so the loop never runs:

for ( int p = 0; p < l; p++ ) {
  // ...
}