Codeforces Round #273 (Div. 2)-A. Initial Bet

最新推荐文章于 2024-02-16 10:04:42 发布

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最新推荐文章于 2024-02-16 10:04:42 发布

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原文链接：http://www.cnblogs.com/angle-qqs/p/4031807.html

本文解析了一个名为“Generosity”的游戏问题，该游戏涉及五位玩家通过传递硬币进行互动。文章提供了一段C语言代码，该代码能根据游戏结束时每位玩家持有的硬币数判断初始投注的硬币数量是否合理，并输出相应的结果。

http://codeforces.com/contest/478/problem/A

There are five people playing a game called "Generosity". Each person gives some non-zero number of coins b as an initial bet. After all players make their bets of b coins, the following operation is repeated for several times: a coin is passed from one player to some other player.

Your task is to write a program that can, given the number of coins each player has at the end of the game, determine the size b of the initial bet or find out that such outcome of the game cannot be obtained for any positive number of coins b in the initial bet.

Input

The input consists of a single line containing five integers c1, c2, c3, c4 and c5 — the number of coins that the first, second, third, fourth and fifth players respectively have at the end of the game (0 ≤ c1, c2, c3, c4, c5 ≤ 100).

Output

Print the only line containing a single positive integer b — the number of coins in the initial bet of each player. If there is no such value of b, then print the only value "-1" (quotes for clarity).

   Sample test(s)
  
     input
    
2 5 4 0 4

     output
    
3

     input
    
4 5 9 2 1

     output
    
-1

Note

In the first sample the following sequence of operations is possible:

One coin is passed from the fourth player to the second player;
One coin is passed from the fourth player to the fifth player;
One coin is passed from the first player to the third player;
One coin is passed from the fourth player to the second player.

解题思路：能够将硬币平均分给5个人，有一个trick就是开始都为0

1 #include <stdio.h>
2
3 int main(){
4      int a, sum = 0, t = 5;
5      while(t--){
6         scanf( " %d ", &a);
7         sum += a;
8     }
9     printf( " %d\n ", sum >= 5 && sum % 5 == 0 ? sum / 5 : - 1);
10      return 0;
11 }

转载于:https://www.cnblogs.com/angle-qqs/p/4031807.html