【codeforces 761A】Dasha and Stairs

time limit per test2 seconds
memory limit per test256 megabytes
inputstandard input
outputstandard output
On her way to programming school tiger Dasha faced her first test — a huge staircase!

The steps were numbered from one to infinity. As we know, tigers are very fond of all striped things, it is possible that it has something to do with their color. So on some interval of her way she calculated two values — the number of steps with even and odd numbers.

You need to check whether there is an interval of steps from the l-th to the r-th (1 ≤ l ≤ r), for which values that Dasha has found are correct.

Input
In the only line you are given two integers a, b (0 ≤ a, b ≤ 100) — the number of even and odd steps, accordingly.

Output
In the only line print “YES”, if the interval of steps described above exists, and “NO” otherwise.

Examples
input
2 3
output
YES
input
3 1
output
NO
Note
In the first example one of suitable intervals is from 1 to 5. The interval contains two even steps — 2 and 4, and three odd: 1, 3 and 5.

【题目链接】:http://codeforces.com/contest/761/problem/A

【题解】

一段区间里面,偶数和奇数的个数的差的绝对值不会超过1;
但是有个Hack点0 0;
一段区间里面不可能既没有奇数也没有偶数;

【完整代码】

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

int a,b;

int main()
{
    cin >> a >> b;
    int temp = abs(a-b);
    if (temp<=1)
    {
        if (a==0 && b==0)
            puts("NO");
        else
            puts("YES");
    }
    else
        puts("NO");
    return 0;
}