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-&…

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…

传送门:Problem 3061 https://www.cnblogs.com/violet-acmer/p/9793209.html 马上就要去上课了,先献上二分AC代码,其余的有空再补 题意: 给定长度为 n 的整数数列 a[0,1,2,........,n]以及整数 S. 求出总和不小于 S 的连续子序列的长度的最小值. 如果解不存在,则输出 0. 题解: 1.二分 由于所有的元素都大于 0 ,所以数组a[ ] 的前缀和sum[ ]为递增的序列,满足二分的条件. 首先确定子序列的起点为s…

<题目链接> 题目大意: 给你一段长度为n的整数序列,并且给出一个整数S,问你这段序列中区间之和大于等于S的最短区间长度是多少. 解题分析:本题可以用二分答案做,先求出前缀和,然后枚举区间长度,然后再判断其是否合法即可,复杂度$O(nlog(n))$.同时,尺取法也是一个不错的选择,通过不断的移动区间的头.尾指针来寻求答案,复杂度为 $O(n)$. 尺取法: #include <cstdio> #include <cstring> #include <algori…

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…

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…

Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9236   Accepted: 3701 Description A sequence of N positive integers (10 < N < 100 000), each of them less than or equal 10000, and a positive integer S (S < 100 000 000) are…

传送门 参考资料: [1]:http://www.voidcn.com/article/p-huucvank-dv.html 题意: 题意就是找一个连续的子区间,使它的和的绝对值最接近target. 题解: 这题的做法是先预处理出前缀和,然后对前缀和进行排序,再用尺取法贪心的去找最合适的区间. 要注意的是尺取法时首尾指针一定不能相同,因为这时区间相减结果为0,但实际上区间为空,这是不存在的,可能会产生错误的结果. 处理时,把(0,0)这个点也放进数组一起排序,比单独判断起点为1的区间更方便. 还…

描述 http://poj.org/problem?id=3061 给定长度为n的数列整数以及整数S.求出总和不小于S的连续子序列的长度的最小值,如果解不存在输出0. Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 11604   Accepted: 4844 Description A sequence of N positive integers (10 < N < 100 000), eac…