题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1541 思路:要求求出不同等级的星星的个数,开始怎么也想不到用树状数组,看完某些大神的博客之后才用树状数组写的,搞了好久才懂得数组的更新过程 #include<cstdio> #include<iostream> #include<algorithm> #include<math.h> #include<string.h> #include<ve…

一開始想,总感觉是DP,但是最后什么都没想到.还暴力的交了一发. 然后開始写线段树,结果超时.感觉自己线段树的写法有问题.改天再写.先把树状数组的写法贴出来吧. ~~~~~~~~~~~~~~~~~~~~~~~~ 树状数组不懂的去看刘汝佳的大白书,那个图画得非常清楚. 题目大意:星星的坐标以y递增的顺序给出,这些点的左下方的点数代表这个点的级数,问0~N-1的级数有多少个?事实上y根本木实用. 题目链接:http://poj.org/problem?id=2352 http://acm.hdu.e…

题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=1541 题意 求每个等级的星星有多少个 当前这个星星的左下角 有多少个 星星 它的等级就是多少 和它同一水平线的左边的星星 以及 同一竖直线的下边的星星也算在内 思路 因为题目给出的x y 坐标 是按照 以 y 为第一关键词 x 为第二关键词 排序后给出的 那么 对于当前的星星来说,在它之前给出的星星中,都是在它下边的 所以 我们就可以不用管 Y 坐标 只用X 坐标 形成一个序列 就是求这个序列的 所…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1541 题目意思:有 N 颗星星,每颗星星都有各自的等级.给出每颗星星的坐标(x, y),它的等级由所有比它低层(或者同层)的或者在它左手边的星星数决定.计算出每个等级(0 ~ n-1)的星星各有多少颗. 我只能说,题目换了一下就不会变通了,泪~~~~ 星星的分布是不是很像树状数组呢~~~没错,就是树状数组题来滴! 按照题目输入,当前星星与后面的星星没有关系.所以只要把 x 之前的横坐标加起来就可以了…

Stars Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 41521   Accepted: 18100 Description Astronomers often examine star maps where stars are represented by points on a plane and each star has Cartesian coordinates. Let the level of a st…

Problem Description Astronomers often examine star maps where stars are represented by points on a plane and each star has Cartesian coordinates. Let the level of a star be an amount of the stars that are not higher and not to the right of the given…

 Problem Description Astronomers often examine star maps where stars are represented by points on a plane and each star has Cartesian coordinates. Let the level of a star be an amount of the stars that are not higher and not to the right of the giv…

Problem Description Astronomers often examine star maps where stars are represented by points on a plane and each star has Cartesian coordinates. Let the level of a star be an amount of the stars that are not higher and not to the right of the given…

Stars Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 15951    Accepted Submission(s): 5945 Problem Description Astronomers often examine star maps where stars are represented by points on a pla…

题意:求坐标0到x间的点的个数 思路:线段树,主要是转化,根据题意的输入顺序,保证了等级的升序,可以直接求出和即当前等级的点的个数,然后在把这个点加入即可. 注意:线段树下标从1开始,所以把所有的x加1存储. #include<iostream> #include<stdio.h> #include<string.h> using namespace std; #define MAXN 32005 #define MAXL 15005 int ans; int lev[…