UVA10557-XYZZY

就是找正环，再找路径，详细的待以后再讨论

先贴上代码：

dfs+dfs：

#include <iostream>
#include <cstring>
using namespace std;
struct Room{
int value,count;
int list[100];
};
Room room[150];
int n, value[150], visit[150] = {0, 0, 0};;
void input()
{
for(int i = 1; i <= n; i++)
{
cin>>room[i].value>>room[i].count;
int len = room[i].count;
for(int j = 0; j < len; j++)
cin>>room[i].list[j];
value[i] = 0;
}
}
int ddfs(int u)
{
if(u==n)return 1;
for(int i = 0; i < room[u].count; i++)
{
if(!visit[room[u].list[i]]){
visit[room[u].list[i]] = 1;
if(ddfs(room[u].list[i]))
return 1;}
}
return 0;
}
int dfs(int u, int e)
{
if(e<=0)return 0;
if(u==n)return 1;
value[u] = e + room[u].value;
for(int i = 0; i < room[u].count; i++)
{
if(!value[room[u].list[i]]){if(dfs(room[u].list[i],e+room[u].value)) return 1;}
else if(value[u]+room[room[u].list[i]].value>value[room[u].list[i]]&&memset(visit,0,sizeof(visit)),ddfs(room[u].list[i]))
return 1;
}
return 0;
}
int main ()
{
while(cin>>n&&n!=-1)
{
input();
if(dfs(1,100))cout<<"winnable"<<endl;
else cout<<"hopeless"<<endl;
}
return 0;
}

dfs+bfs：

#include <iostream>
using namespace std;
struct Room{
int value,count;
int list[100];
};
Room room[150];
int n, value[150];
void input()
{
for(int i = 1; i <= n; i++)
{
cin>>room[i].value>>room[i].count;
int len = room[i].count;
for(int j = 0; j < len; j++)
cin>>room[i].list[j];
value[i] = 0;
}
}
int bfs(int u)
{
int q[150], visit[150] = {0, 0, 0};
int front = 0, rear = 0;
q[0] = u;
while(front>=rear)
{
int r = q[rear];
for(int i = 0; i < room[r].count; i++)
{
if(visit[room[r].list[i]])continue;
if(room[r].list[i]==n)return 1;
q[++front] = room[r].list[i];
visit[room[r].list[i]] = 1;
}
rear++;
}
return 0;
}
int dfs(int u, int e)
{
if(e<=0)return 0;
if(u==n)return 1;
value[u] = e + room[u].value;
for(int i = 0; i < room[u].count; i++)
{
if(!value[room[u].list[i]]){if(dfs(room[u].list[i],e+room[u].value)) return 1;}
else if(value[u]+room[room[u].list[i]].value>value[room[u].list[i]]&&bfs(room[u].list[i]))
return 1;
}
return 0;
}
int main ()
{
while(cin>>n&&n!=-1)
{
input();
if(dfs(1,100))cout<<"winnable"<<endl;
else cout<<"hopeless"<<endl;
}
return 0;
}


都是16秒过的、