int sum_all_subArray_cumulativeMethode(int arr[][300], int n){
int pre[300][300] ;
//adding row wiae -->
for (int i = 0; i < n; i++)
{
int temp = 0;
for (int j = 0; j < n; j++)
{
temp += arr[i][j];
pre[i][j] += temp;
}
}
//adding column wise -->
for (int i = 0; i < n; i++)
{
int temp = 0;
for (int j = 0; j < n; j++)
{
pre[j][i] += temp;
temp += arr[j][i];
}
}
//printing the prefix sum array -->
cout<<endl;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
cout<<pre[i][j]<<" ";
}
cout<<endl;
}
int sum = 0;
//cumulative sum method -->
for (int li = 0; li < n; li++)
{
for (int lj = 0; lj < n; lj++)
{
for (int bi = li; bi < n; bi++)
{
for (int bj = lj; bj < n; bj++)
{
sum += pre[bi][bj] - pre[li - 1][bj] - pre[bi][lj -1] + pre[li -1][lj -1];
}
}
}
}
return sum;
}