poj-3669

来源：互联网发布：中档女装品牌知乎编辑：程序博客网时间：2024/06/04 19:19
http://poj.org/problem?id=3669
广搜
#include<stdio.h>#include<iostream>#include<math.h>#include<stdlib.h>#include<ctype.h>#include<algorithm>#include<vector>#include<string.h>#include<queue>#include<stack>#include<set>#include<map>#include<sstream>#include<time.h>#include<utility>#include<malloc.h>#include<stdexcept>using namespace std;int n;struct ss{    int x;    int y;    int tm;}p[50010];int pp[333][333];//最小被砸时间 初始无穷大int vis[333][333];int dir[4][2] = {{1,0},{-1,0},{0,1},{0,-1}};bool cmp (ss a ,ss b){    return a.tm < b.tm;}int bfs (){    memset(vis,0,sizeof(vis));    queue<ss> q ;    ss qq ;    ss qqq ;    qq.x = 0;    qq.y = 0;    qq.tm = 0;    q.push(qq);    while (!q.empty())    {        qqq = q.front();        q.pop();        for(int i=0;i<4;i++)        {            qq = qqq;            qq.x = qq.x + dir[i][0];            qq.y = qq.y + dir[i][1];            qq.tm = qq.tm+1;            if(qq.x>=0 && qq.y>=0 && qq.tm < pp[qq.x][qq.y] && !vis[qq.x][qq.y] )            {                vis[qq.x][qq.y] = 1;                if (pp[qq.x][qq.y] > p[n-1].tm)                {                    return qq.tm;                }                q.push(qq);            }        }    }    return -1;}int main (){    while (scanf("%d",&n)!=EOF)    {        for(int i=0;i<=322;i++)            for(int j=0;j<=322;j++)            {                pp[i][j] = 10000;            }        for(int i=0;i<n;i++)        {            scanf("%d %d %d",&p[i].x,&p[i].y,&p[i].tm );        }        //对陨石降落时间排序        sort(p,p+n,cmp);        for(int i=0;i<n;i++)            for(int j=0;j<4;j++)            {                if (pp[p[i].x][p[i].y] > p[i].tm)                    pp[p[i].x][p[i].y] = p[i].tm;                int xx = p[i].x + dir[j][0];                int yy = p[i].y + dir[j][1];                if (xx >= 0 && yy >= 0 && pp[xx][yy] > p[i].tm)                {                    pp[xx][yy] = p[i].tm;                }            }        if(pp[0][0] == 0)        {            printf("-1\n");        }        else        {            printf("%d\n",bfs());        }    }    return 0;}
0 0