题解 | #判断两个IP是否属于同一子网#

#include <stdio.h>
int main() {
    int ip[3][4] = {0};
    for (int i = 0; i < 3; i++) {
        scanf("%d.%d.%d.%d", &ip[i][0], &ip[i][1], &ip[i][2], &ip[i][3]);
    }
    if (ip[0][0] != 255 || ip[0][3] != 0) {
        printf("1");
        return 0;
    }
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 4; j++) {
            if (ip[i][j] > 255 || ip[i][j] < 0) {
                printf("1");
                return 0;
            }
        }
    }
    int flag = 0;
    for (int j = 0; j < 4; j++){
        if ((ip[0][j]&ip[1][j])!=(ip[0][j]&ip[2][j])) {
            printf("2");
            return 0;
        }
    }
    printf("0");
    return 0;
}