UVA10557-XYZZY

来源：互联网发布：捷克语翻译软件编辑：程序博客网时间：2024/06/05 22:48

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、