题目链接: http://poj.org/problem?id=3061 题目大意:找到最短的序列长度,使得序列元素和大于S. 解题思路: 两种思路. 一种是二分+前缀和.复杂度O(nlogn).有点慢. 二分枚举序列长度,如果可行,向左找小的,否则向右找大的. 前缀和预处理之后,可以O(1)内求和. #include "cstdio" #include "cstring" ],n,s,a,T; bool check(int x) { int l,r; ;i+x-&…

Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The au…

jessica's Reading PJroblem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9134   Accepted: 2951 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent litt…

http://poj.org/problem?id=2566: Bound Found Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 2237   Accepted: 692   Special Judge Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aero…

Jessica's Reading Problem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7467   Accepted: 2369 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent littl…

题目链接 Description Farmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are facing forward, like good cows. Some of them are facing backward, though, and he needs them all to face forward to make his life perfect. Fortunately,…

1.POJ 3320 2.链接:http://poj.org/problem?id=3320 3.总结:尺取法,Hash,map标记 看书复习,p页书,一页有一个知识点,连续看求最少多少页看完所有知识点 必须说,STL够屌.. #include<iostream> #include<cstring> #include<cmath> #include<queue> #include<algorithm> #include<cstdio>…

http://poj.org/problem?id=3320 题意:给出一串数字,要求包含所有数字的最短长度. 思路: 哈希一直不是很会用,这道题也是参考了别人的代码,想了很久. #include<iostream> #include<algorithm> #include<string> #include<cstring> using namespace std; ; int n; int len; //开散列法,也就是用链表来存储,所以下面的len是从P…

尺取法:顾名思义就是像尺子一样一段一段去取,保存每次的选取区间的左右端点.然后一直推进 解决问题的思路: 先移动右端点 ,右端点推进的时候一般是加 然后推进左端点,左端点一般是减 poj 2566 题意:从数列中找出连续序列,使得和的绝对值与目标数之差最小 思路: 在原来的数列开头添加一个0 每次找到的区间为 [min(i,j)+1,max(i,j)] 应用尺取法的代码: while (r <=n) { int sub = pre[r].sum - pre[l].sum; while (abs(…

Jessica's Reading Problem Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a ve…