// C code for Maximum size square
// sub-matrix with all 1s
#include <stdio.h>
#define bool int
#define R 6
#define C 5
void printMaxSubSquare(bool M[R][C])
{
int i, j;
int S[R][C];
int max_of_s, max_i, max_j;
/* Set first column of S[][]*/
for (i = 0; i < R; i++)
S[i][0] = M[i][0];
/* Set first row of S[][]*/
for (j = 0; j < C; j++)
S[0][j] = M[0][j];
/* Construct other entries of S[][]*/
for (i = 1; i < R; i++) {
for (j = 1; j < C; j++) {
if (M[i][j] == 1)
S[i][j] = min(S[i][j - 1], S[i - 1][j],
S[i - 1][j - 1])
+ 1;
else
S[i][j] = 0;
}
}
/* Find the maximum entry, and indexes of maximum entry
in S[][] */
max_of_s = S[0][0];
max_i = 0;
max_j = 0;
for (i = 0; i < R; i++) {
for (j = 0; j < C; j++) {
if (max_of_s < S[i][j]) {
max_of_s = S[i][j];
max_i = i;
max_j = j;
}
}
}
printf("Maximum size sub-matrix is: \n");
for (i = max_i; i > max_i - max_of_s; i--) {
for (j = max_j; j > max_j - max_of_s; j--) {
printf("%d ", M[i][j]);
}
printf("\n");
}
}
/* UTILITY FUNCTIONS */
/* Function to get minimum of three values */
int min(int a, int b, int c)
{
int m = a;
if (m > b)
m = b;
if (m > c)
m = c;
return m;
}
/* Driver function to test above functions */
int main()
{
bool M[R][C] = { { 0, 1, 1, 0, 1 }, { 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 } };
printMaxSubSquare(M);
getchar();
}