题目链接:poj3669 Meteor Shower 我只想说这题WA了后去看讨论才发现的坑点,除了要注意原点外,流星范围题目给的是[0,300],到302的位置就绝对安全了... #include<cstdio> #include<cmath> #include<queue> #include<cstring> #include<algorithm> #define CLR(a,b) memset((a),(b),sizeof((a))) us…

Meteor Shower Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 12642   Accepted: 3414 Description Bessie hears that an extraordinary meteor shower is coming; reports say that these meteors will crash into earth and destroy anything they h…

Description Bessie hears that an extraordinary meteor shower is coming; reports say that these meteors will crash into earth and destroy anything they hit. Anxious for her safety, she vows to find her way to a safe location (one that is never destroy…

-->Meteor Shower Descriptions: Bessie听说有场史无前例的流星雨即将来临:有谶言:陨星将落,徒留灰烬.为保生机,她誓将找寻安全之所(永避星坠之地).目前她正在平面坐标系的原点放牧,打算在群星断其生路前转移至安全地点. 此次共有M (1 ≤ M ≤ 50,000)颗流星来袭,流星i将在时间点Ti (0 ≤ Ti  ≤ 1,000) 袭击点 (Xi, Yi) (0 ≤ Xi ≤ 300; 0 ≤ Yi ≤ 300).每颗流星都将摧毁落点及其相邻四点的区域. Bess…

Description Bessie hears that an extraordinary meteor shower is coming; reports say that these meteors will crash into earth and destroy anything they hit. Anxious for her safety, she vows to find her way to a safe location (one that is never destroy…

Description Bessie hears that an extraordinary meteor shower is coming; reports say that these meteors will crash into earth and destroy anything they hit. Anxious for her safety, she vows to find her way to a safe location (one that is never destroy…

https://vjudge.net/problem/POJ-3669 先给地图a[][]预处理每个位置被砸的最小时间.然后再bfs. 纯bfs,还被cin卡了下时间.. #include<iostream> #include<cstdio> #include<queue> #include<cstring> #include<algorithm> #include<cmath> #include<stack> #defi…

http://poj.org/problem?id=3669 注意理解题意:有m颗行星将会落在方格中(第一象限),第i颗行星在ti时间会摧毁(xi,yi)这个点和四周相邻的点,一个人开始在原点,然后只能在第一象限内行走,每单位时间移动一格,只能移动到当前未摧毁的点,问多少时间能到达安全地方. 开始题意理解错了,没有明白每一颗行星最多摧毁5个点,我们可以预处理出被行星摧毁的点,然后用bfs搜索. #include <iostream> #include <cstdio> #inclu…

Description 去年偶们湖南遭受N年不遇到冰冻灾害,现在芙蓉哥哥则听说另一个骇人听闻的消息: 一场流星雨即将袭击整个霸中,由于流星体积过大,它们无法在撞击到地面前燃烧殆尽, 届时将会对它撞到的一切东西造成毁灭性的打击.很自然地,芙蓉哥哥开始担心自己的 安全问题.以霸中至In型男名誉起誓,他一定要在被流星砸到前,到达一个安全的地方 (也就是说,一块不会被任何流星砸到的土地).如果将霸中放入一个直角坐标系中, 芙蓉哥哥现在的位置是原点,并且,芙蓉哥哥不能踏上一块被流星砸过的土地.根据预 报,…

题目链接: https://vjudge.net/problem/POJ-3669 题目大意: 巨大流星雨即将袭来.每个流星会对击中的地方以及周围(上下左右四格)造成破坏.Bessie开始时位于(0, 0)位置,并希望逃到一处不会被袭击到的地方(在第一象限内).已知每移动一格需要1个时间单位,被流星破坏后的地方不能再进入.给出M个流星在T时刻击中的地方(X, Y),问Bessie能否逃到安全的地方,若能输出最短时间,否则输出-1. 思路: 预处理出每个点的最小爆炸时间,然后从(0,0)开始BFS…