all:

gcc -O2 -o test maximal_square.c

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

static inline int min(int a, int b)

{

return a < b ? a : b;

}

static inline int max(int a, int b)

{

return a > b ? a : b;

}

static int maximalSquare(char** matrix, int matrixRowSize, int matrixColSize)

{

int i, j, max_len = 0;

int **lens = malloc(matrixRowSize * sizeof(int *));

for (i = 0; i < matrixRowSize; i++) {

lens[i] = malloc(matrixColSize * sizeof(int));

}

for (i = 0; i < matrixColSize; i++) {

lens[0][i] = matrix[0][i] == '1' ? 1 : 0;

max_len = matrix[0][i] == '1' ? 1 : max_len;

}

for (i = 0; i < matrixRowSize; i++) {

lens[i][0] = matrix[i][0] == '1' ? 1 : 0;

max_len = matrix[i][0] == '1' ? 1 : max_len;

}

for (i = 1; i < matrixRowSize; i++) {

for (j = 1; j < matrixColSize; j++) {

if (matrix[i][j] == '1') {

lens[i][j] = 1;

lens[i][j] += min(lens[i - 1][j - 1], min(lens[i - 1][j], lens[i][j - 1]));

} else {

lens[i][j] = 0;

}

max_len = max(max_len, lens[i][j]);

}

}

return max_len * max_len;

}

int main(int argc, char **argv)

{

if (argc < 2) {

fprintf(stderr, "Usage: ./test row1 row2...\n");

exit(-1);

}

int i, j;

int row_size = argc - 1;

int col_size = strlen(argv[1]);

for (i = 0; i < row_size; i++) {

printf("%s\n", argv[i + 1]);

}

printf("%d\n", maximalSquare(argv + 1, argc - 1, strlen(argv[1])));

return 0;

}