http://poj.org/problem?id=1089 Intervals Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 7214   Accepted: 2862 Description There is given the series of n closed intervals [ai; bi], where i=1,2,...,n. The sum of those intervals may be rep…

There is given the series of n closed intervals [ai; bi], where i=1,2,...,n. The sum of those intervals may be represented as a sum of closed pairwise non−intersecting intervals. The task is to find such representation with the minimal number of inte…

Chiaki has n intervals and the i-th of them is [li, ri]. She wants to delete some intervals so that there does not exist three intervals a, b and c such that aintersects with b, b intersects with c and c intersects with a. Chiaki is interested in the…

关于差分约束详情可阅读:http://www.cppblog.com/menjitianya/archive/2015/11/19/212292.html 题意: 给定n个区间[L,R], 每个区间至少放w个球, 问最后整个区间最少要放多少个球. 分析: 假设d[i] 是 [1,i] 至少有多少个点被选中, 特殊地, d[0] = 0. 每个区间的描述可以转化为d[R] - d[L-1] >= w.(因为d[L]也要选中, 左闭右闭区间, 所以要减d[L-1])因为d[i]描述了一个求和函数,所…

Given a collection of intervals, merge all overlapping intervals. For example,Given [1,3],[2,6],[8,10],[15,18],return [1,6],[8,10],[15,18]. 思路: 我们首先要做的就是给区间集排序,由于我们要排序的是个结构体,所以我们要定义自己的comparator,才能用sort来排序,我们以start的值从小到大来排序,排完序我们就可以开始合并了,首先把第一个区间存入结果…

题目: Given a collection of intervals, merge all overlapping intervals. Example 1: Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6]. Example 2: Input: [[1,4]…

/* *区间贪心.前几天刚做了POJ 1328 ...思路完全相同... *最多有100个表情,100行文字.遍历寻找每个表情的所在区间.时间复杂度大约在10^5 ~ 10^6 可以接受. *然后对每个表情按照右坐标排序.改变表情的最右边的字符.贪心判断是否更改. *(⊙o⊙)… 每一行的里的表情可能是重复的.所以判断每行要更改的最少字母数.最后求和.很傻逼的全都放一起了.然后....幸福的wa了. */ #include<stdio.h> #include<iostream> #…

非常经典的区间贪心思想 -- 详见博文: 贪心思想之区间贪心 本题给定一个区间的集合,找到需要移除区间的最小数量,使剩余区间互不重叠. 注意: 可以认为区间的终点总是大于它的起点. 区间 [1,2] 和 [2,3] 的边界相互"接触",但没有相互重叠. 示例 1: 输入: [ [1,2], [2,3], [3,4], [1,3] ] 输出: 1 解释: 移除 [1,3] 后,剩下的区间没有重叠. 示例 2: 输入: [ [1,2], [1,2], [1,2] ] 输出: 2 解释: 你…

描述 The bustling town of Siruseri has just one sports stadium. There are a number of schools, colleges, sports associations, etc. that use this stadium as the venue for their sports events. Anyone interested in using the stadium has to apply to the Ma…

题意:又是中文题... 析:先说一下区间贪心的一个定理,选择不相交的区间:数轴上有n个开区间(ai, bi).选择尽量多的区间,使得这些区间两两不相交,贪心策略是,一定是选bi小的.(想一下为什么). 知道这个的话,这个问题还不so easy!先对每个节目结束的时间排序,然后一个一个的选,保证没有相交,也就是说当前的开始时间一定要是上一个后面或者上一个刚结束当前就开始就OK了. 代码如下: #include <iostream> #include <cstdio> #include…