Sum of all submatix from a given matrix(brute-force approach)

#1

#include
using namespace std;
int main(){
int a[10][10];
int n;
cin>>n;
int sum=0;
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
cin>>a[i][j];
}
}
for(int li=0;li<n;li++){
for(int lj=0;lj<n;lj++){
for(int bi=li+1;bi<n;bi++){
for(int bj=lj+1;bj<n;bj++){

				for(int i=li;i<=bi;i++){
					for(int j=lj;j<=bj;j++){
						sum=sum+a[i][j];
					}
				}
			}
		}
	}
}

}
is this code correct?

Not able to convert the logic into code for 2*2 matrix it give output 2
Wrong answer from the brute force technique
2D array submatrix approach 1
I can't able to implement the code
#2

Yes it is alright. According to the brute force solution as mentioned in the video, 1 x 1 matrix is not included.
To include that you just have to modify the loops for bottom right coordinates. Just begin these loops from top left coordinate values.

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#3

i already started it from top left coordinates.
Ans should be 16,but it is showing 4.

#4

for(int bi=li+1;bi<n;bi++){
for(int bj=lj+1;bj<n;bj++){

These must start from li and lj. Change this and check.

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I'm not getting the correct answer
#5

okay…i got it…
Thanx

I used this technique but not getting desired output
#6

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1 Like