【习题 7-1 UVA-208】Firetruck

【链接】 我是链接,点我呀:)
【题意】

在这里输入题意

【题解】

预处理一下终点能到达哪些点。 暴力就好。 输出结果的时候,数字之间一个空格。。

【代码】

/*
  	1.Shoud it use long long ?
  	2.Have you ever test several sample(at least therr) yourself?
  	3.Can you promise that the solution is right? At least,the main ideal
  	4.use the puts("") or putchar() or printf and such things?
  	5.init the used array or any value?
  	6.use error MAX_VALUE?
  	7.use scanf instead of cin/cout?
  	8.whatch out the detail input require
*/
/*
    一定在这里写完思路再敲代码!!!
*/
#include <bits/stdc++.h>
using namespace std;

const int N = 30;

int k;
int g[N+10][N+10];
bool can[N+10];
int a[N+10];
int vis[N+10],total;

void dfs(int x){
    if (can[x]) return;
    can[x] = 1;
    for (int i = 0;i <= N;i++)
        if (g[x][i]) dfs(i);
}

void dfs1(int x,int dep){
    if (x==k){
        total++;
        cout <<1;
        for (int i = 1;i < dep;i++){
            cout <<' '<<a[i];
        }
        cout << endl;
        return;
    }
    vis[x] = true;
    if (!can[x]) return;
    for (int i = 0;i <= N;i++)
        if (g[x][i] && !vis[i]){
            a[dep] = i;
            dfs1(i,dep+1);
        }
    vis[x] = false;
}

int main(){
	#ifdef LOCAL_DEFINE
	    freopen("rush_in.txt", "r", stdin);
	#endif
	ios::sync_with_stdio(0),cin.tie(0);
	int kase = 0;
    while (cin >> k){
        total = 0;
        cout <<"CASE "<<++kase<<":"<<endl;

        memset(can,0,sizeof can);
        memset(g,0,sizeof g);
        int x,y;
        while(cin >> x >> y){
            if (x==0 && y==0) break;
            g[x][y] = 1;
            g[y][x] = 1;
        }
        dfs(k);
        memset(vis,0,sizeof vis);
        a[0] = 1;
        dfs1(1,1);
        cout <<"There are "<<total<<" routes from the firestation to streetcorner "<<k<<"."<<endl;
    }
	return 0;
}