题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5178 pairs Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3090    Accepted Submission(s): 1085 Problem Description John has n points on the X axi…

<题目链接> 题目大意: 给定一个整数序列,求出绝对值小于等于k的有序对个数. 解题分析: $O(nlong(n))$的二分很好写,这里就不解释了.本题尺取$O(n)$也能做,并且效率很不错. 尺取: #include <bits/stdc++.h> using namespace std; )]; int main(){ int T,n,k;scanf("%d",&T); while(T--){ scanf("%d%d",&…

HDU 5178 pairs(双指针) Hdu 5178 解法:因为要求的是绝对值小于等于k,因此数字的序号关系并不重要,那么排序后使用双指针即可解决这个问题. #include<queue> #include<cmath> #include<cstdio> #include<cstring> #include<cstdlib> #include<iostream> #include<algorithm> #define…

pairs 问题描述 John 在X轴上拥有nn个点,他们的坐标分别为$(x[i],0),(i=0,1,2,…,n-1)$. 他想知道有多少对< a,b ><a,b>满足|x[b]-x[a]| \leq k(a < b)∣x[b]−x[a]∣≤k(a<b). 输入描述 第一行包含一个正整数TT(大约5),表示有多少组数据. 对于每一组数据,先读入两个数n,k(1 \leq n \leq 100000,1 \leq k \leq {10}^{9})n,k(1≤n≤1000…

Problem Description John has n points on the X axis, and their coordinates are (x[i],),(i=,,,…,n−). He wants to know how many pairs<a,b> that |x[b]−x[a]|≤k.(a<b)   Input The first line contains a single integer T (about ), indicating the number o…

题意: X坐标上有n个数.JOHN想知道有多少对数满足:x[a]-x[b]<=k(题意给)[a<b] 思路: 额,,,直接看代码吧,,,, 代码: int T,n,k; int x[100005]; int main(){ cin>>T; while(T--){ cin>>n>>k; rep(i,1,n) scanf("%d",&x[i]); sort(x+1,x+1+n); ll ans=0; rep(i,2,n){ ll te…

pairs Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 4157    Accepted Submission(s): 1481 Problem Description John has n points on the X axis, and their coordinates are (x[i],0),(i=0,1,2,-,n−1…

http://acm.hdu.edu.cn/showproblem.php?pid=4750 题意: 定义f(u,v)为u到v每条路径上的最大边的最小值..现在有一些询问..问f(u,v)>=t的点对有所少对,注意(1,2)和(2,1)是不同的点对 分析: 原来最小生成树有一个很鬼畜的结论,那就是一个图的最小生成树中任意两个点的路径中的最大边一定最小.(妈蛋,完全不知道这个) 然后此题就变得很明朗了,用kruskal算法,加边的时候此边连接的两个集合的路径中的最大边就是这个边,存储下来,询问的时…

pairs Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2037    Accepted Submission(s): 732 Problem Description John has n points on the X axis, and their coordinates are (x[i],0),(i=0,1,2,…,n−1).…

Problem Description During a programming contest, teams cannot sit close to each other, because then a team might copy the solution of another team. You are given the locations of the teams and the minimum required Euclidian distance between two team…