hdu 1242 Resuce

来源：互联网发布：杭州的医疗大数据公司编辑：程序博客网时间：2024/06/05 20:10

题意：X代表卫兵，a代表终点，r代表起始点，.代表路，#代表墙

路花费一秒，x花费两秒

问到达终点的最少时间

思路：BFS+优先队列的果题

#include <cstdio>#include <iostream>#include <cstring>#include <string>#include <cstdlib>#include <algorithm>#include <cmath>#include <set>#include <list>#include <queue>using namespace std;#define L(i) i<<1#define R(i) i<<1|1#define INF 0x3f3f3f3f#define pi acos(-1.0)#define maxn 100010#define mem(a) memset(a,0,sizeof(a))const double eps = 1e-10;char map[210][210];int vis[210][210];int n,m,ans,sx,sy,ax,ay;int mx[4] = {0,0,1,-1};int my[4] = {1,-1,0,0};struct node{    int x,y,t;    node(int x,int y,int t):x(x),y(y),t(t){}    bool operator <(const node a) const    {        return t > a.t;    }};void bfs(){    node st(sx,sy,0);    priority_queue<node> q;    q.push(st);    while(!q.empty())    {        st = q.top();        q.pop();        if(st.x == ax && st.y == ay)        {            printf("%d\n",st.t);            return;        }        for(int i = 0; i < 4; i++)        {            int dx = st.x + mx[i];            int dy = st.y + my[i];            if(dx < 0 || dx >= n || dy < 0 || dy >= m)                continue;            if(map[dx][dy] == '#')                continue;            if(vis[dx][dy])                continue;            vis[dx][dy] = 1;            node ss(dx,dy,st.t+1);            if(map[dx][dy] == 'x')                ss.t++;            q.push(ss);        }    }    printf("Poor ANGEL has to stay in the prison all his life.\n");}int main(){    while(scanf("%d%d",&n,&m) != EOF)    {        for(int i = 0; i < n; i++)            scanf("%s",map[i]);        for(int i = 0; i < n; i++)            for(int j = 0; j < m; j++)        {            if(map[i][j] == 'a')            {                ax = i;                ay = j;            }            if(map[i][j] == 'r')            {                sx = i;                sy = j;            }        }        mem(vis);        bfs();    }    return 0;}

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