Why my code is giving segmentation fault?

#1

#include
#include
using namespace std;
void create_prefix_sum(int** p,int n,int m)
{
for(int i=0;i<n;i++)
{
for(int j=0;j<m;j++)
{
if(j!=0)
p[i][j]+=p[i][j-1];
}
}
for(int i=0;i<n;i++)
{
for(int j=0;j<m;j++)
{
if(i!=0)
p[i][j]+=p[i-1][j];
}
}
}
void display_prefix_sum(int** p,int n,int m)
{
for(int i=0;i<n;i++)
{
for(int j=0;j<m;j++)
cout<<p[i][j]<<" ";
cout<<endl;
}
}
int max_sum(int** p,int n,int m)
{
int max_sum=INT_MIN;
int current_sum=0;
for(int b=0;b<n;b++)
{
for(int l=0;l<m;l++)
{
for(int B=b;B<n;B++)
{
for(int L=l;L<m;L++)
{
current_sum=p[B][L]-p[B][l-1]-p[b-1][L]+p[b-1][l-1];
if(current_sum>max_sum)
max_sum=current_sum;
}
}
}
}
return max_sum;
}
int main()
{
int n,m;
cin>>n>>m;
int** a=new int*[n];
for(int i=0;i<n;i++)
a[i]=new int[m];
for(int i=0;i<n;i++)
{
for(int j=0;j<m;j++)
cin>>a[i][j];
}
create_prefix_sum(a,n,m);
display_prefix_sum(a,n,m);
int x=max_sum(a,n,m);
cout<<x;
return 0;
}

#2

@namangarg31 in create prefix sum function you are doing p[i][j] += p[i][j-1] it will give error for j = 0 because you cannot access negative indices. Please share your code using ide.codingblocks.com in the future.

#3

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