SUM OF ALL SUBMATRIX

#1

int main()
{
int n,m;
int presum=0;
cin>>n>>m;
int a[100][100]={0};
int pre[100][100]={0};

// input the array and adds the elements in rows
for(int i=0;i<n;i++)
{
    for(int j=0;j<m;j++)
    {
        cin>>a[i][j];
        presum+=a[i][j];
        pre[i][j]=presum;
    }
    presum=0;
}

// adds the elements  in columns
for(int j=0;j<m;j++)
{
    for(int i=0;i<n;i++)
    {
        presum+=pre[i][j];
        pre[i][j]=presum;
    }
    presum=0;
}

cout<<endl;

int sum=0;

for(int ti=0;ti<n;ti++)
{
    for(int tj=0;tj<m;tj++)
    {
        for(int bi=ti;bi<n;bi++)
        {
            for(int bj=tj;bj<m;bj++)
            {
                sum+=pre[bi][bj]-pre[ti-1][bj]-pre[bi][tj-1]+pre[ti-1][tj-1];
            }
        }
    }
}

cout<<sum;
return 0;

}

Can you check for the mistake.The only correct answer it gives are for a 2x2 arrray.

#2

hi @anasmir24
i have check your code
it is giving correct ans

for which input it is giving wrong ans??

#3

i checked the same code in coding blocks ide.It shows the correct answer but for some reason in vs code it shows wrong answer.Like for e.g in a 3x3 matrix with all elemnts 1 the result it gives is 1251484712

#4

okay then consider ans of online ide as correct

because this may be your compiler error

if your doubt is resolved Please mark it as resolved