強連通、強連通縮點建圖

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;

#define CLR(arr,v) memset(arr,v,sizeof(arr))
const int MaxV = 105,MaxE = 10005;

int Connect[MaxV],H[MaxV],Num[MaxE],Next[MaxE],Len[MaxE],Ind[MaxV],Low[MaxV],Stack[MaxV],InStack[MaxV],top,ind,pos,ConnectNum;

void Clear()
{
	pos = top = ind = ConnectNum = 0;
	CLR(H,-1); CLR(InStack,false);
	CLR(Low,0);CLR(Ind,0);
}

void add(int u,int v,int c)
{
	Num[pos] = v;
	Len[pos] = c;
	Next[pos] = H[u];
	H[u] = pos++;
}

void Dfs(int cur)
{
	Low[cur] = Ind[cur] = ++ind;
	Stack[top++] = cur;
	InStack[cur] = true;
	for(int i = H[cur];i != -1;i = Next[i])
	{
		if(!Ind[ Num[i] ])
		{
			Dfs(Num[i]);
			Low[cur] = min(Low[cur],Low[ Num[i] ]);
		}
		else if(InStack[ Num[i] ])
			Low[cur] = min(Low[cur],Ind[ Num[i] ]);
	}
	if(Low[cur] == Ind[cur])
	{
		int s;
		ConnectNum++;
		do{
			s = Stack[--top];
			InStack[s] = false;
			Connect[s] = ConnectNum;
		}while(s != cur);
	}
}
int Tarjan(int n)
{
	for(int i = 1;i <= n;++i)
		if(!Ind[i]) Dfs(i);
	return ConnectNum;
}

int graph[MaxV][MaxV];
//將縮點後的圖存入graph鄰接矩陣中，如果邊上有權值，須考慮實際情況修改建圖代碼
void BuildGraph(int n) 
{
	for(int i = 1;i <= n;++i)
		for(int j = H[i];j != -1;j = Next[j])
			if(Connect[i] != Connect[ Num[j] ])
				graph[ Connect[i] ][ Connect[Num[j]] ] = Len[j];
}