题意:给你一组数a[n],求满足a[i] < a[k] < a[j] (i <= k <= j)的最大的 j - i . 析:在比赛时,我是暴力做的,虽然错了好多次,后来说理解是rmq,我又用rmq写了一次,发现rmq还没有我暴力快,rwq 2000多,暴力才700. 暴力中加了一个优化条件就是前枚举 i 时,下一个 i 值不一定是i+1,而是满足条件中的最大值的位置.这样优化就是时间很短了. 如果用rmq,就得用两个dp数组分别记录最大值和最小值的下标,然后枚举 i,在i+1 -…

RMQ+二分....枚举 i  ,找比 i 小的第一个元素,再找之间的第一个最大元素.....                   Sticks Problem Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 9338   Accepted: 2443 Description Xuanxuan has n sticks of different length. One day, she puts all her stick…

一.题目 Sticks Problem 二.分析 对于$i$和$j$,并没有很好的方法能同时将他们两找到最优值,所以考虑固定左端点$i$. 固定左端点后,根据题意,$a[i]$是最小值,那么现在的问题就转化成了求以$a[i]$为左端点最小值的范围内,找到一个最大值$a[j]$的$j$,然后相减就是以$i$为左端点的最优值. 然后枚举$i$,找到最大的$j-i$即可. 如何找$j$,预先用ST表预处理好最大值最小值,然后先找以$i$为最小值的管辖范围(二分找,因为如果当前位置$pos$如果不满足,…

Interviewe Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6722    Accepted Submission(s): 1592 Problem Description YaoYao has a company and he wants to employ m people recently. Since his compa…

Sticks Problem's Link:   http://poj.org/problem?id=1011 Mean: http://poj.org/problem?id=1011&lang=zh-CN&change=true analyse: 爆搜,但是其中蕴含着很多剪枝. Time complexity: O(n^2) Source code:  // Memory Time // 1347K 0MS // by : Snarl_jsb // 2014-11-07-17.14 #i…

Sticks Problem poj-2452 题目大意:给你一串n个数的数列a,上面的数为a1到an.我们求最大的y-x,其中,y和x满足1.x<y 2.任意的x<i<y,都有ai>ax&&ai<ay. 注释:n<=50000,ai<=100000 想法:我们很容易就想到,松弛x.那么,对于任意的x,y都必须满足这样的条件,就是说y和x之间的所有数,都大于ax.那么,我们就可以处理出任意的x右边的第一个比ax小的数的下标为r[x].这样,我们就可…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5289 题意:给你n个数和k,求有多少的区间使得区间内部任意两个数的差值小于k,输出符合要求的区间个数 思路:求出区间的最大最小值,只要他们的差值小于k,那么这个区间就符合要求,但是由于n较大,用暴力一定超时,所以就要用别的方法了:而RMQ是可以求区间的最值的,而且预处理的复杂度只有O(nlogn),而查询只是O(1)处理,这样相对来说节约了时间,再根据右端点来二分枚举左端点(其实不用二分好像更快,估…

Interviewe Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4543    Accepted Submission(s): 1108 Problem Description YaoYao has a company and he wants to employ m people recently. Since his compa…

Get Luffy Out Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8851   Accepted: 3441 Description Ratish is a young man who always dreams of being a hero. One day his friend Luffy was caught by Pirate Arlong. Ratish set off at once to Arlo…

Assignment Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 557    Accepted Submission(s): 280 Problem Description Tom owns a company and he is the boss. There are n staffs which are numbered fr…