题解 | #小乐乐改数字#

#include <stdio.h>
#include <math.h>



int main() {
    int a, b = 0, ret, count,tmp;
    count = 0;;
    scanf("%d", &a);
    ret = a;
    tmp = a;

    while (ret % 10 != 0) {

        if (ret % 2 == 0) {
            ret = ret / 10 * 10;
            b = b + (a - ret) * pow(10, count);
            count++;
        } else {
            ret = ret / 10 * 10 + 1;
            b = (a - ret) * pow(10, count) + b;
            count++;
        }
        ret = ret / 10;
        a = a / 10;

    }
    printf("%d", tmp - b);
}