强连通分量两种算法。tarjan和kosaraju

/***********************************************\
|Author: YMC
|Created Time: 2014/5/10 22:36:04
|File Name: tarjan.cpp
|Description:
\***********************************************/
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <string>
#include <cstring>
#include <algorithm>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>

using namespace std;
#define maxn 100005
int n;
int stop;
int cnt;
int visitnum;
int dfn[maxn];
int low[maxn];
bool instack[maxn];
int stap[maxn];
int belong[maxn];
#define mod  1000000007
vector<int>tree[maxn];
void tarjan(int i){
int j;
dfn[i] = low[i] = ++visitnum;
instack[i] = true;
stap[++stop] = i;
for(int k=0;k<tree[i].size();k++){
j = tree[i][k];
if(!dfn[j]){
tarjan(j);
if(low[j]<low[i]) low[i] = low[j];
}
else if(instack[j] && dfn[j]<low[i]) low[i] = dfn[j];
}
if(dfn[i] == low[i]){
cnt++;
do{
j = stap[stop--];
instack[j] = false;
belong[j] = cnt;
}
while(j!=i);
}
}
void solve(){
stop = cnt = visitnum = 0;
memset(dfn,0,sizeof(dfn));
for(int i=1;i<=n;++i){
if(!dfn[i]) tarjan(i);
}
}
long long val[maxn];
long long ma[maxn];
long long mb[maxn];
#define inf 0x7fffffff
int main() {
//freopen("input.txt","r",stdin);
n = 6;
tree[1].push_back(3);
tree[1].push_back(2);
tree[2].push_back(4);
tree[3].push_back(5);
tree[3].push_back(4);
tree[4].push_back(1);
tree[4].push_back(6);
tree[5].push_back(6);
solve();
for(int i=1;i<=n;++i){
cout<<belong[i]<<" ";
}
cout<<endl;

return 0;
}

/***********************************************\
|Author: YMC
|Created Time: 2014/5/11 20:26:18
|File Name: mykosaraju.cpp
|Description:
\***********************************************/
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <string>
#include <cstring>
#include <algorithm>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>

using namespace std;
#define maxn 100
int v;
vector <int> G[maxn];
vector <int> rG[maxn];
vector <int> vs;
bool used[maxn];
int cmp[maxn];
void add_edge(int from,int to){
G[from].push_back(to);
rG[to].push_back(from);
}
void dfs(int v){
used[v] = true;
for(int i=0;i<G[v].size();++i){
if(!used[G[v][i]]) dfs(G[v][i]);
}
vs.push_back(v);
}
void rdfs(int v,int k){
used[v] = true;
cmp[v] = k;
for(int i=0;i<rG[v].size();++i){
if(!used[rG[v][i]]) rdfs(rG[v][i],k);
}
}
int scc(){
memset(used,false,sizeof(used));
vs.clear();
for(int i=0;i<v;++i){
if(!used[i]) dfs(i);
}
memset(used,false,sizeof(used));
int k = 1;
for(int i=vs.size()-1;i>=0;--i){
if(!used[vs[i]]) rdfs(vs[i],k++);
}
return k;
}
int main() {
//freopen("input.txt","r",stdin);
v = 6;
for(int i=1;i<=6;++i){
G[i].clear();
rG[i].clear();
}
add_edge(1,3);
add_edge(1,2);
add_edge(2,4);
add_edge(3,5);
add_edge(3,4);
add_edge(4,1);
add_edge(4,6);
add_edge(5,6);
scc();
for(int i=1;i<=v;++i){
cout<<cmp[i]<<" ";
}
cout<<endl;
return 0;
}