题目描述
Xiao Ming’s parents visit ZJU and Xiao Ming want to take them to look around the campus.They will start from the stone with two famous question raised by President Zhu Kezhen and end at largest dining room in Asia.They want to visit every place exactly once in ZJU’s campus,including the stone and dining room.
输入
The input consists of multiple test cases.
The first line contains an integer n(n<=20),which means the number of place in ZJU’s campus.We give numbers(from 1 to n) to the places,especailly,1 means the stone with two famous question and n means the largest dining room.
The second line contains an integer m,which means the number of roads between two place.
Then follows m lines,each line contain two integer,which means there is a road between these two place.The road will not repeat more than one time.
输出
For each test case, you should output one line.If the path exists,you should output 1.Otherwise,you should output 0.
样例输入
5
4
1 2
1 3
1 4
2 5
6
6
1 3
3 2
1 2
3 4
4 5
5 6
样例输出
0
1
来源
2013年浙江大学复试机试模拟题
#include<stdio.h>
#include<string.h>
int n,m,ok;
int vis[22],Map[22][22];
//搜索，已经访问count个地方现在处于location点
void DFS(int location,int count)
{
int i;
//已经全部访问完
if(count == n){
//到达目的地n
if(location == n){
ok = 1;
}
return;
}
//没有访问完，访问下一处
for(i = 1;i <= n;i++){
//i点没访问过且能访问则去i点
if(Map[location][i] == 1&& vis[i] == 0){
//标记i已经访问过
vis[i]=1;
//递归下一处
DFS(i,count+1);
if(ok == 1){
return;
}
//取消标记
vis[i] = 0;
}
}
}
//初始化
void Init()
{
int i,j,start,end;
//初始化地图
for(i = 1;i <= n;i++){
for(j = 1;j <= n;j++){
Map[i][j]=0;
}
}
//添加路况
for(i = 0;i < m;i++){
scanf("%d %d",&start,&end);
//end和start之间联通
Map[start][end]=1;
Map[end][start]=1;
}
memset(vis,0,sizeof(vis));
ok = 0;
//1为出发点
vis[1]=1;
}
int main()
{
while(scanf("%d %d",&n,&m)!=EOF){
Init();
DFS(1,1);
printf("%d\n",ok);
}
return 0;
}
