Description In the ``Four Color Map Theorem" was proven with the assistance of a computer. This theorem states that every map can be colored using only four colors, in such a way that no region is colored using the same color as a neighbor region. He…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4751 思路:构建新图,对于那些两点连双向边的,忽略,然后其余的都连双向边,于是在新图中,连边的点是能不在同一个图中的,于是我们可以用dfs染色的方法来判断是否存矛盾. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vector> u…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4751 题目大意:判断一堆人能否分成两组,组内人都互相认识. 解题思路:如果两个人不是相互认识,该两人之间连边.最终构成一张图,二分匹配. #include<cstdio> #include<cstring> #include<iostream> using namespace std; #define maxn 105 #define maxm 20010 int n,e;…

和以前做过的一个二分图颇为相似,以前的是互相不认识的放在一组,这个是互相认识的,本质上是相同的 是 hdu 2444 #include<cstdio> #include<iostream> #include<algorithm> #include<cstring> #include<cmath> #include<queue> #include<map> using namespace std; typedef long…

题目链接 Divide Groups Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1153    Accepted Submission(s): 418 Problem Description   This year is the 60th anniversary of NJUST, and to make the celebrati…

题目链接 比赛时候,建图建错了.大体算法想到了,不过很多细节都没想好. #include <cstdio> #include <cstring> #include <cmath> #include <queue> #include <algorithm> using namespace std; ]; ][]; ][]; int n,z; void dfs(int x,int step) { int i; if(z) return ; ; i &…

一道很简单的题,不过在比赛的时候没有写出来: 刚刚看到这个题,我以为是一个图论题,后来发现其实就是一个暴力的题: 用bfs,因为一个人与他不认识的人肯定不会在一个集合,如果判断出现冲突则分配失败,否则就成功: 代码: #include<cstdio> #include<cstring> #include<queue> #define maxn 103 using namespace std; int map[maxn][maxn],n; int b[maxn]; boo…

Problem Description   This year is the 60th anniversary of NJUST, and to make the celebration more colorful, Tom200 is going to invite distinguished alumnus back to visit and take photos.   After carefully planning, Tom200 announced his activity plan…

SDUST的训练赛 当时死磕这个水题3个小时,也无心去搞其他的 按照题意,转换成无向图,预处理去掉单向的边,然后判断剩下的图能否构成两个无向完全图(ps一个完全图也行或是一个完全图+一个孤点) 代码是赛后看的网上大神,所以转载过来了,dfs染色的时候很巧妙,巧妙的用到了就两个无向完全图 #include <cstdio> #include <cstring> #include <cmath> #include <vector> #include <qu…

Divide Groups Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 423    Accepted Submission(s): 161 Problem Description   This year is the 60th anniversary of NJUST, and to make the celebration mor…