C. Friends and Gifts Codeforces Round #611 (Div. 3)题意:给定的一维数组中,每i个元素为f(i),f(i)有两种取值,若f(i)为0,表示第i人不知道将礼物给谁,若f(i)>=1&&f(i)<=n表示第i人将礼物送给第f(i)人,要注意题目规定每个人只能收一件礼物也只能发一件礼物给别人,而且不能自己给自己送礼物,...
There arenn friends who want to give gifts for the New Year to each other. Each friend should giveexactly one gift and receiveexactly one gift. The friendcannot give the gift to himself. For each friend the valuefifi is known: it is eitherfi=0fi=0 if theii-th friend doesn't know wh...
There are nn friends who want to give gifts for the New Year to each other. Each friend should giveexactlyone gift and receiveexactlyone gift. The friendcannotgive the gift to himself. For each friend the value fifi is known: it is either fi=0fi=0 if the ii-th friend doesn't know ...
注意到,一张有向图的节点入度和等于出度和,而第11、22类点入出度均相等,所以第33类点一定可以和第44类点两两匹配。 当所有点变成第11类点时,匹配即完成。 参考代码: #include <cstdio>intn, a,in[200010],out[200010], ans[200010];intaa[200010], bb[200010], cc[200010], cnt, k, s1, s2, s...
[Codeforces Round #611 (Div. 3)] C. Friends and Gifts (随机大法好) C. Friends and Gifts time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are nn friends who want to give gifts for the New Year to each other. Each frien...