10020 Given several segments of line (int the X axis) with coordinates [Li, Ri]. You are to choose the minimalamount of them, such they would completely cover the segment [0, M].InputThe first line is the number of test cases, followed by a blank lin…

Given several segments of line (int the X axis) with coordinates [Li, Ri]. You are to choose the minimal amount of them, such they would completely cover the segment [0, M].InputThe first line is the number of test cases, followed by a blank line.Eac…

 Minimal coverage  The Problem Given several segments of line (int the X axis) with coordinates [Li,Ri]. You are to choose the minimal amount of them, such they would completely cover the segment [0,M]. The Input The first line is the number of test…

Minimal coverage The Problem Given several segments of line (int the X axis) with coordinates [Li,Ri]. You are to choose the minimal amount of them, such they would completely cover the segment [0,M]. The Input The first line is the number of test ca…

问题来源:刘汝佳<算法竞赛入门经典--训练指南> P81: 问题描述:你的任务是在n*n(1<=n<=5000)的棋盘上放n辆车,使得任意两辆车不相互攻击,且第i辆车在一个给定的矩形R之内. 问题分析:1.题中最关键的一点是每辆车的x坐标和y坐标可以分开考虑(他们互不影响),不然会变得很复杂,则题目变成两次区间选点问题:使得每辆车在给定的范围内选一个点,任何两辆车不能选同一个点.  2.本题另外一个关键点是贪心法的选择,贪心方法:对所有点的区间,按右端点从小到大排序:每次在一个区间…

UVA 11389 Time Limit:1000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu Description II U C   ONLINE   C ON TEST   2 008 The Bus Driver Problem Input: standard input Output: standard output In a city there are n bus drivers. Also there are n …

题目链接:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1095 题目大意:有许多只王八,每一只王八有着两个属性,重量w和力量s,这些王八最多能叠多少层不会让出现王八被压死,注意王八承受的重量 要算上自己的重量 思路分析:首先是贪心,我们要选择力量最大的王八放在下面是最优的,证明如下 分析,如果力量大的在下面,力量小的在上面,那么力量大的…

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=961 贪心,排序,对左端点贪,找最大右端点. #include <cstdio> #include <cstring> #include <algorithm> #define maxn 6000000 using namespace std; int t,…

题意: 数轴上有n个闭区间[ai, bi],选择尽量少的区间覆盖一条指定线段[0, m] 算法: [start, end]为已经覆盖到的区间 这是一道贪心 把各个区间先按照左端点从小到大排序,更新start为end,如果区间1在start的右端,则无解,因为其他区间更不可能覆盖到 然后在剩下的能覆盖到start的区间里面选择能覆盖到最右端的区间并更新end,然后记录在path里面.如果end的已经将m覆盖则退出循环 如果遍历完所有的区间后end依然没能覆盖到start,则无解 最后按照parh里…

题意: 有司机,下午路线,晚上路线各n个.给每个司机恰好分配一个下午路线和晚上路线. 给出行驶每条路线的时间,如果司机开车时间超过d,则要付加班费d×r. 问如何分配路线才能使加班费最少. 分析: 感觉上是要先排序,然后时间最长的路线配另一个时间最短的路线. 这里就严格证明一下这样贪心的正确性. 以两条路线为例,其他情况都是类似的: 不妨假设:A1≥A2,B1≤B2,水平线代表d 情况一: 如图,司机一要付加班费,司机二不用,如果我们将B1.B2交换: 因为B1≤B2,所以付给司机一的加班费不会…