Drazil and Date
Someday, Drazil wanted to go on date with Varda. Drazil and Varda live on Cartesian plane. Drazil's home is located in point (0, 0) and Varda's home is located in point (a, b). In each step, he can move in a unit distance in horizontal or vertical direction. In other words, from position (x, y) he can go to positions (x + 1, y), (x - 1, y), (x, y + 1) or (x, y - 1).
Unfortunately, Drazil doesn't have sense of direction. So he randomly chooses the direction he will go to in each step. He may accidentally return back to his house during his travel. Drazil may even not notice that he has arrived to (a, b) and continue travelling.
Luckily, Drazil arrived to the position (a, b) successfully. Drazil said to Varda: "It took me exactly s steps to travel from my house to yours". But Varda is confused about his words, she is not sure that it is possible to get from (0, 0) to (a, b) in exactly s steps. Can you find out if it is possible for Varda?
Input
You are given three integers a, b, and s ( - 109 ≤ a, b ≤ 109, 1 ≤ s ≤ 2·109) in a single line.
Output
If you think Drazil made a mistake and it is impossible to take exactly s steps and get from his home to Varda's home, print "No" (without quotes).
Otherwise, print "Yes".
Examples
Input
5 5 11
Output
No
Input
10 15 25
Output
Yes
Input
0 5 1
Output
No
Input
0 0 2
Output
Yes
Note
In fourth sample case one possible route is: (0,0)——(0,1)——(0,0)。
问题链接:https://vjudge.net/problem/CodeForces-515A
问题分析:
1.最小步数为a+b,所走的步数必须要大于或等于最小步数,否则直接判断为“NO”;
2.当所走步数大于最小步数时,要确保多出来的步数是2的倍数,即走出去了还要走回来,来回步数是2的倍数;
3.注意要把a,b转化成整数,因为题目中说Drazil没有方向感,即可能走到x轴或y轴的负方向
4.注意数据大小
#include<iostream>
using namespace std;
int main()
{
long long a, b, s;
cin >> a >> b >> s;
if (a < 0)a = -a;
if (b < 0)b = -b;
if (a + b > s)cout << "NO";
else if (( s- a - b) % 2 == 0)cout << "YES";
else cout << "NO";
}