AtCoder 2333 Scc Puzzle （水题）

题目链接：http://abc055.contest.atcoder.jp/tasks/arc069_a?lang=en

C - Scc Puzzle

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Time limit : 2sec / Memory limit : 256MB

Score : 300 points

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:

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

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Input

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

N M

Output

Print the answer.

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Sample Input 1

Copy 1 6

Sample Output 1

Copy 2

Two Scc groups can be created as follows:

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

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Sample Input 2

Copy 12345 678901

Sample Output 2

Copy 175897

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Submit

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

代码：

#include<iostream> #include<algorithm> #include<cstdio> #include<cstring> #include<vector> #include<queue> #include<map> #include<cmath> #define N 1009 using namespace std; const int INF = 0x3f3f3f3f; typedef long long LL; LL fun(LL n, LL m) { if((m / 2) < n) return m / 2; LL ans = n; m = m - n * 2; ans = ans + m / 4; return ans; } int main() { LL n, m; scanf("%lld%lld", &n, &m); LL ans = fun(n, m); printf("%lld\n", ans); return 0; }