Chef Feeds Cats run time error (other)?

help
1

i don’t know what is causing this error as the constraints range is not too large . can anyone tell me what is causing that error?

#include<algorithm>
using namespace std;
int main()
{
    int T;
    //cout<<"enter number of test cases ";
    cin>>T;
    while(T--)
    {
        int N,M;
        //cout<<"enter value of N";
        cin>>N>>M;
        
        int A[M],i,j;
        
        for(i=0;i<M;++i)
        {
            cin>>A[i];
            
        }
        
        int c=0;
        for(i=0;i<M;i+=N)
        {
              sort(A+i,A+(i+N));
            
             for(j=i+1;j<N+i;++j)
             {
                 if(A[j-1]==A[j])
                 {
                     c++;
                 }
             }
        }
        
        if(c==0)
        cout<<"YES"<<endl;
        else
        cout<<"NO"<<endl;
       
       
        
    }
    return 0;
}```
2

Since N > M is possible, let’s consider the test case:

100 1
1

line 26
In the first iteration of the for loop at line 24, the second operand of function sort tries to access a memory location, that really, isn’t legal to access. So, that’s producing a Segmentation Fault. :slightly_smiling_face:

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3 
        {
        for(i=0;i<M;i+=N)
        {
              sort(A+i,A+(i+N));
            
             for(j=i+1;j<N+i;++j)
             {
                 if(A[j-1]==A[j])
                 {
                     c++;
                 }
             }
        }
        }

is this gonna solve the issue as now it will enter only when M>1

4

I’m sorry I don’t quite think that that’s going to work either. When your code runs against my test case, even for M = 2, it’s going to try to access location &A[0] + 0x00000063 in the first iteration itself and that’s going to cause a Seg. Fault because A is only 8 bytes long. You may take a look at this documented piece of C++14 code. I tried explaining every part. I hope that helps. :slightly_smiling_face:

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