In how many ways can you choose k elements out of n elements, not taking order into account? Write a program to compute this number. Input The input will contain one or more test cases. Each test case consists of one line containing two integers n (n…

Binomial Showdown TimeLimit: 1 Second   MemoryLimit: 32 Megabyte Totalsubmit: 2323   Accepted: 572 Description In how many ways can you choose k elements out of n elements, not taking order into account? Write a program to compute this number. Input…

Binomial Showdown Time Limit: 2 Seconds      Memory Limit: 65536 KB In how many ways can you choose k elements out of n elements, not taking order into account? Write a program to compute this number. Input The input will contain one or more test cas…

Binomial Showdown Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 18457   Accepted: 5633 Description In how many ways can you choose k elements out of n elements, not taking order into account?  Write a program to compute this number. In…

// n 个 数 取 k个数的取法// C(n,k) 注意些细节#include <iostream> #include <string> #include<sstream> #include <cmath> #include <map> #include <stdio.h> #include <string.h> #include <algorithm> using namespace std; #defin…

http://acm.sdut.edu.cn/sdutoj/problem.php?action=showproblem&problemid=1061 题意 : 表示这个题的英文没看懂,就看懂了一个warning,看着样例像组合数就算了一下,结果真是. 组合数这种题,一共有好多代码,但基本各种代码放在各种题上就会出现不同的问题,要么是超时问题,或者越界问题,还有的直接WA,超时我倒是好理解,但我不明白的是为什么都是算组合数的还会出现越界和WA这样的错误,难道是数组问题?一直不太肯定,毕竟只有一种…

/* * POJ_2249.cpp * * Created on: 2013年10月8日 * Author: Administrator */ #include <iostream> #include <cstdio> using namespace std; typedef long long int64; int64 work(int64 n , int64 k){ if(k > n/2){ k = n-k; } int64 a = 1; int64 b = 1; int…

Description In how many ways can you choose k elements out of n elements, not taking order into account? Write a program to compute this number. Input The input will contain one or more test cases. Each test case consists of one line containing two i…

题目链接 https://atcoder.jp/contests/agc005/tasks/agc005_e 题解 完了真的啥都不会了-- 首先,显然如果某条A树的边对应B树上的距离大于等于\(3\), 且A能走到该边的某个端点,那么答案就是\(-1\). A能走到某个点当且仅当从A的起点到这个点的路径上每个点与A起点的距离都小于与B起点的距离. 然后直接在A树上从根开始DFS,如果走不到了就返回,否则用与\(y\)的距离更新答案:同时在遍历每条边的时候判断是否可以\(-1\). 时间复杂度\(…

洛谷题面传送门 & Atcoder 题面传送门 记先手移动棋子的树为红树,后手移动棋子的树为蓝树. 首先考虑一个性质,就是如果与当前红色棋子所在的点相连的边中存在一条边,满足这条边的两个端点在蓝树上的距离 \(\ge 3\),那么答案肯定是 \(-1\),因为如果此时红色棋子与蓝色棋子在蓝树上的距离 \(\le 1\),那么先手就可以沿着这条红边将红色棋子移到该边的另一个端点,使红色棋子与蓝色棋子在蓝树上的距离 \(>1\),否则原地不动.如果后手再次将蓝色棋子移到与红色棋子在蓝树上距离为…