Pintando o mapa, C (gcc)

Language: Layout:

#include <stdio.h>

#define TEM_VIZINHO(i, j, w, h, n) (\
        ((i) > 0       && (j) > 0       && image[(i) - 1][(j) - 1] == (n)) || \
        ((i) > 0                        && image[(i) - 1][(j)    ] == (n)) || \
        ((i) > 0       && (j) < (w) - 1 && image[(i) - 1][(j) + 1] == (n)) || \
        (                 (j) > 0       && image[(i)    ][(j) - 1] == (n)) || \
        (                 (j) < (w) - 1 && image[(i)    ][(j) + 1] == (n)) || \
        ((i) < (h) - 1 && (j) > 0       && image[(i) + 1][(j) - 1] == (n)) || \
        ((i) < (h) - 1                  && image[(i) + 1][(j)    ] == (n)) || \
        ((i) < (h) - 1 && (j) < (w) - 1 && image[(i) + 1][(j) + 1] == (n)))

int main() {
    char a, b;
    int w, h; /*largura e altura da matriz respectivamente que o usuario irá mandar como input*/
    int image[300][300];
    int i, j, m, n, achou;
    int island = 1;

scanf("%c%c %d %d", &a, &b, &w, &h);
    printf("%d %d \n", w, h);
    for (i = 0; i < h; i++) {
        for (j = 0; j < w; j++) {
            scanf("%d", &image[i][j]);
        }
    }

/* Numera as ilhas.*/
    for (i = 0; i < h; i++) {
        for (j = 0; j < w; j++) {
            if (image[i][j] == 1 && TEM_VIZINHO(i, j, w, h, 0)) {
                island++;
                image[i][j] = island;
                do {
                    achou = 0;
                    for (m = 0; m < h; m++) {
                        for (n = 0; n < w; n++) {
                            if (image[m][n] == 1 && TEM_VIZINHO(m, n, w, h, island)) {
                                image[m][n] = island;
                                achou = 1;
                            }
                        }
                    }
                } while (achou);
            }
        }
    }

/* Printa a matriz do usuário para debugar. */
    for (i = 0; i < h; i++) {
        printf("\n");
        for (j = 0; j < w; j++) {
            printf("%c", image[i][j] == 0 ? ' ' : image[i][j] + '@' - 1);
        }
    }

printf("\n%d", island - 1);
    return 0;
}

P1
40 22
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 1 1 0 0 1 1 1 1 0 0 0 0 0 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 1 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0
0 1 1 1 1 1 1 1 1 0 1 0 0 1 1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 0 0 0
0 1 1 1 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0
0 1 0 1 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0
0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 0 0 0
0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 0 0 0
0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 0 0 1 0 0 0
0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 1 1 0 1 1 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0
0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 1 1 0 0 0 1 1 0 0
0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 0 0 0 0 0 1 1 1 0 0 0 0
0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 0 0 1 0 0 0 0 0 0 1 1 1 1 1 0 0 0
0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 1
0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Show compiler warnings [ + ] Compiler args [ - ] Show input
Compilation time: 0.13 sec, absolute running time: 0.09 sec, cpu time: 0.03 sec, memory peak: 3 Mb, absolute service time: 0,3 sec