题解

#include <bits/stdc++.h>
using namespace std;

int cl(int num) {
    int maxn = 0;
    int minn = 9;

    while (num > 0) {
        int digit = num % 10;
        maxn = max(maxn, digit);
        minn = min(minn, digit);
        num /= 10;
    }

    return maxn - minn;
}

int fs(int l, int r) {
    int ls = l;
    int ml = cl(l);

    for (int i = l + 1; i <= r; i++) {
        int ln = cl(i);
        if (ln > ml) {
            ls = i;
            ml = ln;
        }
        if (ml == 9) {  // 可以试试去掉这一行，试试就超时
            break;
        }
    }

    return ls;
}

int main() {
    int T;
    cin >> T;

    for (int i = 0; i < T; i++) {
        int l, r;
        cin >> l >> r;

        int ship = fs(l, r);
        cout << ship << endl;
    }

    return 0;
}