Scc Puzzle(水题)

题目链接：https://vjudge.net/contest/276429#problem/A

Problem Statement

Snuke loves puzzles.

Today, he is working on a puzzle using S- and c-shaped pieces. In this puzzle, you can combine two c-shaped pieces into one S-shaped piece, as shown in the figure below:

9b0bd546db9f28b4093d417b8f274124.png
Snuke decided to create as many Scc groups as possible by putting together one S-shaped piece and two c-shaped pieces.

Find the maximum number of Scc groups that can be created when Snuke has N S-shaped pieces and M c-shaped pieces.

Constraints

1≤N,M≤1012

Input

The input is given from Standard Input in the following format:

N M

Output

Print the answer.

Sample Input 1

1 6

Sample Output 1

2
Two Scc groups can be created as follows:

Combine two c-shaped pieces into one S-shaped piece
Create two Scc groups, each from one S-shaped piece and two c-shaped pieces

Sample Input 2

12345 678901

Sample Output 2

175897

题意：输入n个S， m个C，一个S可以由2个C组成，求一共有多少个Scc

解析：先把S与C配对，剩下的C/4 + S的个数就是答案，需要注意的点是当c的个数小于s的个数时，S与C不能完全配对，因此最大组数为c的个数除以2

#include<cstdio>
#include<iostream>

using namespace std;

int main()
{
    long long n,m;
    while(~scanf("%lld%lld",&n,&m))   //多组输入
    {
        cout << ((m/2<n)? m/2 : n+(m-n*2)/4) << endl;  //三目运算符
    }
    return 0;
}

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