题解 | #整数与IP地址间的转换#

#include <stdio.h>

int main() {
    
    unsigned a = 0;
    unsigned b = 0;
    unsigned c = 0;
    unsigned d = 0;
    unsigned e = 0;
    scanf("%u.%u.%u.%u", &a, &b, &c, &d);
    scanf("%u", &e);


    unsigned num = (a<<24) + (b<<16) +  (c<<8) + d;
    printf("%u\n", num);

    //掩码，只看后8位
    d = e & 0xff;
    c = (e >> 8) & 0xff;
    b = (e >> 16) & 0xff;
    a = (e >> 24) & 0xff;
    printf("%u.%u.%u.%u", a, b, c, d);

    return 0;
}