题意: 派会上有n种食物,每种食物有wi份.有m个朋友,每一个朋友有两种他喜欢吃的食物xi,yi.你需要判断他的朋友是否都能吃到食物.如果都能吃到食物,那么要输出朋友来的顺序,不能的话输出"DEAD". 如果一个朋友来的时候发现两种他喜欢的食物都有,那么他会两种食物都吃一份,如果仅有一种食物还有,那么就只吃一份这种食物. 题解: 首先先预处理一下每一种食物有多少人要吃,我们设某种食物的需求量为needi份,如果某种食物的needi<=wi,那么只要喜欢第i种食物的人永远不可能没有…

题目链接:https://codeforces.com/contest/1369/problem/E 题意 Lee 有 $n$ 种不同种类的食物和 $m$ 个朋友,每种食物有 $w_i$ 个,每个朋友喜欢吃两种食物 $x_i, y_i$,如果一个朋友被叫去厨房时一个喜欢吃的食物也没有,他就会吃掉 Lee,否则对还有的他喜欢吃的食物一种吃掉一个,问是否存在一个叫朋友去厨房的顺序保证 Lee 不会被吃掉. 题解 设 $s_i$ 为第 $i$ 种食物共需要多少个,若 $w_i \ge s_i$,则喜欢…

题意: t组输入,你有n个数,还有k个朋友,每一个朋友需要wi个数.意思就是你要给第i个朋友分配wi个数,输入保证w1+w2+...+wk=n 一个朋友的兴奋值是你分配给他的数中最大值加上最小值的和(如果某个朋友只有一个数,那最小值和最大值都是一样的). 题解: 首先对于只需求一个数的朋友,我们应该先处理,给他分配最大的数给他,因为这样这些大数会被加两遍. 然后我们安排剩下的人.我们知道一个人的贡献只和最大值最小值有关,中间那些是什么并不关心,所以我们从拿的最多的那个人开始,因为当前剩下的数中,…

题目链接:https://codeforces.com/contest/1369/problem/C 题意 将 $n$ 个数分给 $k$ 个人,每个人分 $w_i$ 个数($\sum_{i = 1}^{k}w_i = n$),每个人的快乐值为分到数的最小值和最大值之和,计算所有人快乐值之和的最大值. 题解 将 $n$ 个数从小到大排序后从两边加起,利用较大的 $w_i$ 跳过尽可能多的较小值. 代码 #include <bits/stdc++.h> using ll = long long;…

A. Mafia Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/348/problem/A Description One day n friends gathered together to play "Mafia". During each round of the game some player must be the supervisor and other n - 1…

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