--uva247（calling circles）强联通与floyd-warshell

图论题：一开始我是用tarjan算法做的，wrong answer 了很多次，然后又用了floyd-warshell算法，也wa了

最后找了题解，原来最后的dataset后面不是组数，是样例的编号，题根本就没说，让人怎么理解。。。

tarjan

#include<stdio.h>
#include<iostream>
#include<string.h>
#include<string>
#include<map>
#include<algorithm>
#define M 100
using namespace std;

int qis;
int maps[50][50];
int dfn[M],low[M],vis[M],stacks[M];
int belongs[25][50];
int cnt ,scnt,begin,ans;

void init(){
    memset(dfn,0,sizeof(dfn));
    memset(low,0,sizeof(low));
    memset(stacks,0,sizeof(stacks));
    memset(vis,0,sizeof(vis));
    memset(belongs,0,sizeof(belongs));
    memset(maps,0,sizeof(maps));
    qis  = cnt = scnt =  begin  = ans =0;
}

void tarjan(int x){
    int v;
    dfn[x] = low [x] = ++cnt ;
    stacks[++begin] = x;
    for(int i = 1;i<=qis;i++){
        if(maps[x][i]){

            if(!dfn[i]){
                tarjan(i);
                low[x] = min(low[x],low[i]);
            }
            else if(!vis[i]){
                low[x] = min(low[x],dfn[i]);
            }

        }
    }
    if(low[x] == dfn[x]){
        scnt ++;
        do{
            v = stacks[begin--];
            belongs[scnt][++belongs[scnt][0]] = v;//顶点处理
            vis[v] = 1;
        }while(v != x);

        if(belongs[scnt][0]>1)ans ++;

    }
}

int main(){
    int flag = 1;
    int n,m;
    int cases = 1;
    while(scanf("%d%d",&n,&m),n||m){

        string a,b;

        init();

        map<string,int>ms;
        map<int,string>_ms;
        ms.clear();_ms.clear();

        for(int i = 0;i<m;i++){

           cin>>a>>b;
           if(ms[a] == 0)ms[a] = ++qis;
           if(ms[b] == 0)ms[b] = ++qis;
           _ms[ms[a]] = a;
           _ms[ms[b]] = b;
           maps[ms[a]][ms[b]] = 1;

        }

        for(int i  =1;i<= qis;i++){

            if(!dfn[i])tarjan(i);

        }
        if(flag == 1)flag = 0;
        else puts("");

        printf("Calling circles for data set %d:\n",cases++);
        for(int i = 1;i<=scnt;i++){
            int j;
            for(j = 1;j<belongs[i][0];j++)
               cout<<_ms[belongs[i][j]]<<", ";
            cout<<_ms[belongs[i][j]]<<endl;
        }

    }
}

floyd-warshell:

#include<stdio.h>
#include<iostream>
#include<string.h>
#include<string>
#include<map>
#include<algorithm>
#define M 100
using namespace std;

int qis;
int maps[50][50];
int vis[M];
int belongs[25][50];
int scnt ,ans;
int cases = 1;

int main(){
    int flag = 1;
    int n,m;
    while(scanf("%d%d",&n,&m),n||m){
        qis =ans =  scnt = 0;
        string a,b;
        map<string,int>ms;
        map<int,string>_ms;
        ms.clear();_ms.clear();
        memset(vis,0,sizeof(vis));
        memset(maps,0,sizeof(maps));
        memset(belongs,0,sizeof(belongs));
        for(int i = 1;i<=n;i++)maps[i][i] = 1;
        for(int i = 0;i<m;i++){

           cin>>a>>b;
           if(ms[a] == 0)ms[a] = ++qis;
           if(ms[b] == 0)ms[b] = ++qis;
           _ms[ms[a]] = a;
           _ms[ms[b]] = b;
           maps[ms[a]][ms[b]] = 1;

        }

        //floyd
		for(int k = 1;k <= n;k++)
		    for(int i = 1;i <= n;i++)
			    for(int j = 1;j <= n;j++){

    				maps[i][j] = maps[i][j] || (maps[i][k] && maps[k][j]);

    			} 

		for(int i = 1;i<=n;i++){
			if(vis[i] == 0){
				scnt++;
				for(int j = 1;j<=n;j++){

					if(maps[i][j]&&maps[j][i]){
							belongs[scnt][++belongs[scnt][0]] = j;
							vis[j] = 1;
					}

				}
				if(belongs[scnt][0]>1)ans++;
			}

		}
        if(flag == 1)flag = 0;
        else puts("");

        printf("Calling circles for data set %d:\n",cases++);
        for(int i = 1;i<=scnt;i++){
            int j;
            for(j = 1;j<belongs[i][0];j++)
               cout<<_ms[belongs[i][j]]<<", ";
            cout<<_ms[belongs[i][j]]<<endl;
        }

    }
}