P4890 Never·island 求门开的最小时间,其实也就是求门关的最大时间. 坐标这么大....显然坐标要离散化 离散化排序后,我们发现x轴被这些点划分成若干条线段$(l,r)$,并且有4种情况 我们用$v[i]$数组表示给队$i$钥匙的贡献 1.左端点为$i$队的起点,右端点为$i$队的终点:显然队$i$钥匙的贡献包括这一段,$v[i]+=r-l$ 2.左端点为$i$队的终点,右端点为$j$队的起点:无论如何分配钥匙,这一段都可以关门,于是答案可直接算上$r-l$ 3.左端点为$i$队…

传送门 考虑把总区间长度减去最多能减少的区间长度 把所有区间离散化,对每一小段计算贡献 分类讨论一波,对于边界 $i,i+1$ ,设它们之间距离 $d$,$i$ 属于 $x$ 考察队的边界,$i+1$ 属于 $y$ 考察队的边界: $i$ 为左边界,$i+1$ 为左边界,显然如果给 $x$ 钥匙就可以让这一段时间关门,给 $x$ 的贡献 $val[x]$ 加上 $d$ ,表示给 $x$ 钥匙得到的贡献 $i$ 为左边界,$i+1$ 为右边界,如果 $x=y$ ,显然给 $x$ 钥匙就可以让这段时…

You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one isla…

https://leetcode.com/problems/island-perimeter/ 在一个N×N的矩阵中,N<100,1代表岛,0代表海,岛内没有海,求岛的周长 [[0,1,0,0], [1,1,1,0], [0,1,0,0], [1,1,0,0]] Answer: 16 Explanation: The perimeter is the 16 yellow stripes in the image below: 由正方形组成的不规则图形的周长和正方形个数有什么关系? 这个就是这题的…

#463. Island Perimeter You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and th…

原题链接在这里:https://leetcode.com/problems/island-perimeter/ 题目: You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is c…

Description There are N cities and N-1 roads in Magic-Island. You can go from one city to any other. One road only connects two cities. One day, The king of magic-island want to visit the island from the capital. No road is visited twice. Do you know…

B. Island Puzzle time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A remote island chain contains n islands, labeled 1 through n. Bidirectional bridges connect the islands to form a simple c…

D. Bad Luck Island time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The Bad Luck Island is inhabited by three kinds of species: r rocks, s scissors and p papers. At some moments of time two…

6.4 A bunch of people are living on an island, when a visitor comes with a strange order: all blue-eyed people must leave the island as soon as possible. There will be a flight out at 8:00pm every evening. Each person can see everyone else's eye colo…