Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 14698   Accepted: 6205 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) ar…

转自博客:http://blog.chinaunix.net/uid-24922718-id-4848418.html 尺取法就是两个指针表示区间[l,r]的开始与结束 然后根据题目来将端点移动,是一种十分有效的做法.适合连续区间的问题 poj3061 给定长度为n的数列整数a0,a1,a2,a3 ..... an-1以及整数S.求出综合不小于S的连续子序列的长度的最小值.如果解不存在,则输出0. 这里我们拿第一组测试数据举例子,即 n=10, S = 15, a = {5,1,3,5,10,7…

Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 13955   Accepted: 5896 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) ar…

Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 18145   Accepted: 7751 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) ar…

Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9050   Accepted: 3604 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…

题意 : 找出给定序列长度最小的子序列,子序列的和要求满足大于或者等于 S,如果存在则输出最小长度.否则输出 0(序列的元素都是大于 0 小于10000) 分析 : 有关子序列和的问题,都可以考虑采用先构造前缀和的方式来进行接下来的操作 ( 任意子序列的和都能由某两个前缀和的差表示 ). 二分做法 ==> 我们枚举起点,对于每一个起点 St 二分查找看看 St 后面有没有前缀和是大于或者等于 [ St的前缀和 ] + S 的,如果有说明从当前起点开始有一个终点使得起终之和是大于或者等于 S 的,…

题目连接 http://poj.org/problem?id=3061 Subsequence 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 given. Write a program to find the minimal len…

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 given. Write a program to find the minimal length of the subsequence of consecutive elements o…

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 given. Write a program to find the minimal length of the subsequence of consecutive elements o…

http://poj.org/problem?id=3061 题目大意: 给定长度为n的整列整数a[0],a[1],--a[n-1],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. 思路: 方法一: 首先求出各项的和sum[i],这样可以在O(1)的时间内算出区间上的总和,这样,枚举每一个起点i,然后二分搜索出结果大于sum[i]+tot的最小下标.(tot是题目中的S) 总的时间为O(nlogn) 方法二: 设以a[s]开始的总和最初大于S时的连续子序列为a[s]+a[s+1]+--…