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…

Bound Found Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 5207   Accepted: 1667   Special Judge Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration…

Bound Found Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 2277   Accepted: 703   Special Judge Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration…

一.首先介绍一下什么叫尺取 过程大致分为四步: 1.初始化左右端点,即先找到一个满足条件的序列. 2.在满足条件的基础上不断扩大右端点. 3.如果第二步无法满足条件则到第四步,否则更新结果. 4.扩大左端点,并且回到第二步. 很明显如果要这样做,那么这个序列要是一个有顺序的序列,因为这样的话保证左端点不变,右端点一直向右延伸一定会使答案靠近结果.(可以看一道题理解一下) Signals of most probably extra-terrestrial origin have been rec…

Bound Found Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 1651   Accepted: 544   Special Judge Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration…

Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration (that must be going through a defiant phase: "But I want to use feet, not meters!"). Each signal seems to…

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…

Boring count Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 932    Accepted Submission(s): 382 Problem Description You are given a string S consisting of lowercase letters, and your task is cou…

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…

[题目大意] 给出一个整数列,求一段子序列之和最接近所给出的t.输出该段子序列之和及左右端点. [思路] ……前缀和比较神奇的想法.一般来说,我们必须要保证数列单调性,才能使用尺取法. 预处理出前i个数的前缀和,和编号i一起放入pair中,然而根据前缀和大小进行排序.由于abs(sum[i]-sum[j])=abs(sum[j]-sum[i]),可以忽视数列前缀和的前后关系.此时,sum[r]-sum[l]有单调性. 因此我们可以先比较当前sum[r]-sum[l]与t的差,并更新答案. 如果当…