Thread: Find max size sub matrix

Given a binary matrix, find out the maximum size square sub-matrix with all 1
consider the below binary matrix.
0 1 1 0 0
1 1 0 1 0
0 1 1 1 0
1 1 1 1 0
1 1 1 1 1
0 0 0 0 0
Then the result should be
1 1 1
1 1 1
1 1 1

Code:

int n, i, j, answer = 0;
scanf("%d", &n);
for(i = 0; i < n; ++i) {
	scanf("%s", &mx[i]);
	for(j = 0; j < n; ++j)
		if(mx[i][j] == '1')
			size[i][j] = 1;
}
for(i = 1; i < n; ++i)
	for(j = 1; j < n; ++j) {
		if(mx[i][j] == '1')
			size[i][j] = min(size[i][j - 1],
                            min(size[i - 1][j], size[i - 1][j - 1])) + 1;
		if(size[i][j] > answer)
			answer = size[i][j];
	}
for(i = 0; i < answer; ++i) {
	for(j = 0; j < answer; ++j)
		printf("1");
	printf("\n");
}