C++ 代码

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<string>
#include<vector>
#pragma warning(disable:4996)
using namespace std;
const int maxn = 1005;
typedef long long ll;
ll n;
vector<int>num;
int main() {
    int t;
    scanf("%d", &t);
    int cas = 1;
    while (t--) {
        scanf("%lld", &n);
        num.clear();
        ll x = n;
        while (x) {
            num.push_back(x % 10);
            x /= 10;
        }
        ll l = 0, r = 0;
        ll res = 0;
        for (int i = num.size() - 1; i >= 0; i--) {
            int u = num[i];
            if (u % 2 == 0) {
                l = l * 10 + u;
                r = r * 10 + u;
            }
            else {
                l = l * 10 + u - 1;
                for (int j = i - 1; j >= 0; j--) {
                    l = l * 10+8;
                }
                res = n - l;
                if (u != 9) {
                    r = r * 10 + u + 1;
                    for (int j = i - 1; j >= 0; j--) {
                        r = r * 10;
                    }
                    if (res > r - n) {
                        res = r - n;
                    }
                }
                break;
            }
        }
        printf("Case #%d: %lld\n", cas++, res);
    }
    return 0;
}