Counting Sequences Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/65536 K (Java/Others) Total Submission(s): 2335    Accepted Submission(s): 820 Problem Description For a set of sequences of integers{a1,a2,a3,...an}, we define a sequen…

/* n*n暴力 这个很好想 */ #include<cstdio> #define maxn 100010 #define mod 9901 using namespace std; int n,k,a[maxn],f[maxn],ans; int Abs(int a){ ?-a:a; } int max(int a,int b){ return a<b?b:a; } int main() { freopen("cin.txt","r",stdi…

传送门:hdu 5862 Counting Intersections 题意:对于平行于坐标轴的n条线段,求两两相交的线段对有多少个,包括十,T型 官方题解:由于数据限制,只有竖向与横向的线段才会产生交点,所以先对横向线段按x端点排序,每次加入一个线段,将其对应的y坐标位置+1,当出现一个竖向线段时,查询它的两个y端点之间的和即为交点个数. 注意点:对x坐标排序是对所有线段端点排序:因为可能出现 “  1-1  “ 这样的情况,所以对于横着的线段,需要进行首尾x坐标处理:我的方法是对于x坐标,先…

HDU 5862 Counting Intersections(离散化+树状数组) 题目链接http://acm.split.hdu.edu.cn/showproblem.php?pid=5862 Description Given some segments which are paralleled to the coordinate axis. You need to count the number of their intersection. The input data guarant…

hdu 6184 Counting Stars(三元环计数) 题意: 给一张n个点m条边的无向图,问有多少个\(A-structure\) 其中\(A-structure\)满足\(V=(A,B,C,D)\) && \(E=(AB,BC,CD,DA,AC)\) 显然\(A-structure\)是由两个有公共边的三元环构成的 \(1 <=n <= 1e5\) \(1 <= m <= min(2e5,n*(n-1)/2)\) 思路: 三元环计数 做法1. ①统计每个点…

传送门:Hdu 5862 Counting Intersections 题意:有n条线段,每一条线段都是平行于x轴或者y轴,问有多少个交点 分析: 基本的操作流程是:先将所有的线段按照横树坐标x按小的优先排序,注意是所有的线段 :(这里是将线段都去掉只保留两个端点) 然后从左到右的顺序经行扫描,遇到横的线段,如果是左端点对应的 yi 便++ , 若是右端点对应的y1便--:  遇到竖直的线段,便统计区间[y1,y2] 的数 , 看到这了是不是有点东西了呢? 如果我是按照x排序的话,两线段若想相交…

Counting Squares Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 1885    Accepted Submission(s): 946 Problem Description Your input is a series of rectangles, one per line. Each rectangle is sp…

Counting Intersections 题目链接: http://acm.split.hdu.edu.cn/showproblem.php?pid=5862 Description Given some segments which are paralleled to the coordinate axis. You need to count the number of their intersection. The input data guarantee that no two se…

Counting Cliques Time Limit: 8000/4000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 539    Accepted Submission(s): 204 Problem Description A clique is a complete graph, in which there is an edge between every pair…

题目链接: http://acm.split.hdu.edu.cn/showproblem.php?pid=5862 Counting Intersections Time Limit: 12000/6000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others) 问题描述 Given some segments which are paralleled to the coordinate axis. You need to coun…