weixin_45113721的博客

链接：https://www.acwing.com/problem/content/397/任意两点之间至少有两条不相交的路径（点可以相交，边不能相交）变充分必要条件是该图是边双连通图。题目求将一个连通图变为边双连通图至少要加多少条边。无向图经过e-DCC缩点后会变成森林或者一棵树(联通分量内部一定不需要加边)。本题答案为（叶子节点数量+1）/2#include<cstdio>#include<cstring>#include<iostream>#incl

先tarjan缩点 再在拓扑图上找一条最长链#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#include<set>using namespace std;#define ll long longconst int N=1e5+1...

把任意一张有向图变成强连通图，缩点后有p个零入度点，q个零出度点，答案就是max(p,q);特别的，如果图本身就是强连通图答案为0#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;const int N=10...

题目：https://vjudge.net/problem/POJ-2186求从其他所有点可以到达的点的个数#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;const int N=1e4+10;const...

题目：https://www.luogu.com.cn/record/32864490#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;const int N=2e4+10;const int M=2e5+1...

可以解决有重边的图。题目：https://vjudge.net/problem/UVA-796这个题目本身有需要注意的点。#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#include<vector>using namespace...

推荐一个视频：https://www.bilibili.com/video/BV19J411J7AZ?from=search&seid=376629233923966426题目链接：https://www.luogu.com.cn/record/32856562#include<cstdio>#include<iostream>#include<cst...