Thread: Segmentation fault 11

I am trying merge sort an array of 5 numbers. g++ compiles the program without error but i am unable to execute due to segmentation fault 11. I have read the article on segmentation faults. I think writing off array endings might be responsible. How do I correct it?

Code:

:

Code:

#include <fstream>
#include <iostream>


using namespace std;


void sort(int A[], int size)
{
    if (size==1)
            return;
    
    int left[size/2], right[size/2+1], j=0, k=0;
    
    for(int i=1; i<=size; i++)
    {
        if(i<=size)
            left[++j] = A[i];
        else
            right[++k] = A[i];
    }
    
    sort(left, j);
    sort(right, k);
    
    int a=1, l=1, r=1;
    while(l+r <= j+k)
    {
        if((left[l]<right[r]) || (r==k))
            A[a++]=left[l++];
        else
            A[a++]=right[r++];
    }
}        


int main()
{
    int array[5]={4,5,1,0,10};
    
    sort(array, 5);
    
    for(int j=1; j<=5; j++)
        cout<<array[j]<<endl; 
    
    return 1;
}

Originally Posted by Chanakya

I am trying merge sort an array of 5 numbers. g++ compiles the program without error but i am unable to execute due to segmentation fault 11. I have read the article on segmentation faults. I think writing off array endings might be responsible. How do I correct it?

Code:

:

Code:

#include <fstream>
#include <iostream>


using namespace std;


void sort(int A[], int size)
{
    if (size==1)
            return;
    
    int left[size/2], right[size/2+1], j=0, k=0;
    
    for(int i=1; i<=size; i++)
    {
        if(i<=size)
            left[++j] = A[i];
        else
            right[++k] = A[i];
    }
    
    sort(left, j);
    sort(right, k);
    
    int a=1, l=1, r=1;
    while(l+r <= j+k)
    {
        if((left[l]<right[r]) || (r==k))
            A[a++]=left[l++];
        else
            A[a++]=right[r++];
    }
}        


int main()
{
    int array[5]={4,5,1,0,10};
    
    sort(array, 5);
    
    for(int j=1; j<=5; j++)
        cout<<array[j]<<endl; 
    
    return 1;
}

you're doing

left[++j] = A[i];

while your i is from 1 to 5
your array indexes are 0 to 4

that should help you figure out the problems

I have made the above changes but segmentation fault still persists.

Code:

#include <fstream>
#include <iostream>
 
 
using namespace std;
 
 
void sort(int A[], int size)
{
    if (size==1)
            return;
     
    int left[2], right[3], j=0, k=0;
     
    for(int i=0; i<size; i++)
    {
        if(i<=size/2)
            left[j++] = A[i];
        else
            right[k++] = A[i];
    }
     
    sort(left, j);
    sort(right, k);
     
    int a=0, l=0, r=0;
    while(l+r <= j+k)
    {
        if((left[l]<right[r]) || (r==k))
            A[a++]=left[l++];
        else
            A[a++]=right[r++];
    }
}        
 
 
int main()
{
    int array[5]={4,5,1,0,10};
     
    sort(array, 5);
     
    for(int j=0; j<5; j++)
        cout<<array[j]<<endl; 
     
    return 1;
}