CSP 高速公路 强连通分量 tarjan

 

题目：点击打开链接

思路：

 

#include<stdio.h>
#include<vector>
#include<cmath>
#include<string.h>
#define MAXN 10000+5
#define MAXM 100000+5
#include<stack>
using namespace std; 
bool in_stack[MAXN];
bool vis[MAXN];
int low[MAXN];
int dfn[MAXN];
stack<int> s;
int cur_time,color;
int col_num[MAXN];
int n,m;
vector<int> adj[MAXN];
int tarjan(int cur)
	{
		dfn[cur] = low[cur] = ++cur_time;
		s.push(cur);
		in_stack[cur] = true;
		vis[cur] = true;
		for(int i = 0; i < adj[cur].size(); ++i){
			int v = adj[cur][i];
			if(!vis[v]){
				tarjan(v);
				low[cur] = min(low[v],low[cur]);
			}
			else if(in_stack[v]){
				low[cur] = min(low[cur],dfn[v]);
			}
			
		}
		if(dfn[cur] == low[cur]){
			++color;
			int v;
			do{
				v = s.top();
				s.pop();
				in_stack[v] = false;
				++col_num[color];
			}while(v