Codeforces Round #596 (Div. 2, based on Technocup 2020 Elimination Round 2) A. Forgetting Things

链接:

https://codeforces.com/contest/1247/problem/A

题意:

Kolya is very absent-minded. Today his math teacher asked him to solve a simple problem with the equation a+1=b with positive integers a and b, but Kolya forgot the numbers a and b. He does, however, remember that the first (leftmost) digit of a was da, and the first (leftmost) digit of b was db.

Can you reconstruct any equation a+1=b that satisfies this property? It may be possible that Kolya misremembers the digits, and there is no suitable equation, in which case report so.

思路:

特判9 1，其他的照着搞。

代码:

//#include <iostream>
//#include <fstream>
//#include <process.h>
//#include "ch08/ch08Func.cpp"
#include <bits/stdc++.h>
typedef long long LL;
using namespace std;

int main()
{
    ios::sync_with_stdio(false);
    int a, b;
    cin >> a >> b;
    if (a == b)
    {
        cout << a << '1' << ' ' << b << '2' << endl;
        return 0;
    }
    if (a == 9 && b == 1)
    {
        cout << 9 << ' ' << 10 << endl;
        return 0;
    }
    if (a > b || b-a > 1)
    {
        cout << -1 << endl;
        return 0;
    }
    cout << a << '9' << ' ' << b << '0' << endl;

    return 0;
}