[POJ3416]Crossing

【[POJ3416]Crossing】的更多相关文章

Problem 给你n个点,m个询问,每个询问有x, y 问以(x,y)为原点建立的平面直角坐标系分割的第一象限和第三象限的点数和减去第二象限和第四象限的点数和 Solution 用2个树状数组维护一条竖直的线的左右两边的点的分布情况然后对x轴排序,把一个点从右边的树状数组中拿出,放到左边去(相当那条竖直的线在向右扫描) 然后查询处答案即可. Notice 树状数组用0的坑 Code #include<cmath> #include<cstdio> #include<cst…

[LeetCode] Self Crossing 自交

You are given an array x of n positive numbers. You start at point (0,0) and moves x[0] metres to the north, then x[1] metres to the west, x[2] metres to the south, x[3] metres to the east and so on. In other words, after each move your direction cha…

【LeetCode】Self Crossing（335）

1. Description You are given an array x of n positive numbers. You start at point (0,0) and moves x[0] metres to the north, then x[1] metres to the west, x[2] metres to the south, x[3] metres to the east and so on. In other words, after each move you…

还记得高中的向量吗？leetcode 335. Self Crossing（判断线段相交）

传统解法题目来自 leetcode 335. Self Crossing. 题意非常简单,有一个点,一开始位于 (0, 0) 位置,然后有规律地往上,左,下,右方向移动一定的距离,判断是否会相交(self crossing). 一个很容易想到的方案就是求出所有线段,然后用 O(n^2) 的时间复杂度两两判断线段是否相交,而线段相交的判断,可以列个二元一次方程求解(交点).这个解法非常容易想到,但是实际操作起来比较复杂,接下去介绍利用向量的解法. 向量解法简单回顾下向量,具体的自行谷歌.向量就…

Crossing River

Crossing River 题目链接:http://acm.hust.edu.cn/vjudge/problem/visitOriginUrl.action?id=26251 题意: N个人希望去过河,但每次只能过两个且要有一个人把船划回来接其他的人: 两个人一起过河所用的时间是两个人中单独过河时间最多的: 求所有人过河所需要的最少的时间. 思路分析: 定义一个装n个人中每个人过河所需要的时间数组a[]:并用sort进行从小到大进行排序. 求将最慢的和次慢的运过去所需的最少时间,下面有两种可能…

Leetcode: Self Crossing

You are given an array x of n positive numbers. You start at point (0,0) and moves x[0] metres to the north, then x[1] metres to the west, x[2] metres to the south, x[3] metres to the east and so on. In other words, after each move your direction cha…

POJ 1700 Crossing River (贪心)

Crossing River Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 9585 Accepted: 3622 Description A group of N people wishes to go across a river with only one boat, which can at most carry two persons. Therefore some sort of shuttle arrangem…