(2016弱校联盟十一专场10.3) B.Help the Princess!

题目链接

宽搜一下就行。

#include <iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
int n,m;
char str[][];
int to[][]={,,-,,,,,-};
bool mp[][];
bool check(int x,int y)
{
    if(x<||x>=n||y<||y>=m)return ;
    if(str[x][y]=='#'||mp[x][y]==)return ;
    return ;
}
int prx,pry;
struct node
{
    int x,y,time;
};

bool bfs(int posx,int posy)
{
    int pt=-,st=-;
    queue<node>Q;
    node a,next;
    mp[posx][posy]=;
    a.x=posx,a.y=posy,a.time=;
    Q.push(a);
    while(!Q.empty())
    {
        a=Q.front();
        Q.pop();
        if(st==-&&str[a.x][a.y]=='$') {
            st = a.time+;
        }
        if(str[a.x][a.y]=='@'&&pt==-) {
            pt = a.time+;
        }
        if(pt!=-&&st!=-) {
            if(pt>=st) return ;
            else return ;
        }
        for(int i=;i<;i++)
        {
            next=a;
            next.x+=to[i][];
            next.y+=to[i][];
            if(check(next.x,next.y))continue;
            next.time=a.time+;
            mp[next.x][next.y]=;
            Q.push(next);
        }
    }
    if(pt!=-)
        return ;
    else return ;
}
int main()
{
   // freopen("cin.txt","r",stdin);
    while(~scanf("%d%d",&n,&m))
    {
        int posx,posy;
        memset(mp,,sizeof(mp));
        for(int i=;i<n;i++)
        {
            scanf("%s",str[i]);
            for(int j=;j<m;j++)
                if(str[i][j]=='%')
            {
                posx=i;
                posy=j;
            }
        }
        if(bfs(posx,posy))puts("Yes");
        else puts("No");
    }
    return ;
}