题目链接:http://codeforces.com/contest/1169/problem/B 题意:给你 m 对数 ,问你能不能在 1 − n 之间找到俩个不相等的 x 和 y 使得 对于前面每一对之中至少有一个数可以等于 x 或 y,找得到输出 YES,否则输出NO. 思路:假设第一对为(a‚b),若x ,y存在,那么他们其中之一就在第一对(a‚b)中,那么如果存在(c,d)使得 c,d 与 a,b 完全不同,那么 x 和 y 另一个数就在(c,d)中,所以 x–y 就是 a–c.…
C. Foe Pairs 题目连接: http://www.codeforces.com/contest/652/problem/C Description You are given a permutation p of length n. Also you are given m foe pairs (ai, bi) (1 ≤ ai, bi ≤ n, ai ≠ bi). Your task is to count the number of different intervals (x, y…
链接:https://codeforces.com/contest/1169/problem/B 题意: Toad Ivan has mm pairs of integers, each integer is between 11 and nn, inclusive. The pairs are (a1,b1),(a2,b2),…,(am,bm)(a1,b1),(a2,b2),…,(am,bm). He asks you to check if there exist two integers …
Codeforces 1404 D.Game of Pairs 给定\(2n\)个数\(1,2,...,2n\),A 和 B 将进行交互,规则如下: A 需要将元素分成 n 组 \(\mathbf{pair}\)(二元组) B 从每组 \(\mathbf{pair}\)中选择一个元素,如果权值和是 \(2n\) 的倍数,那么 B 胜,否则 A 胜. 你需要选择 A/B 中的一者扮演角色,并取得胜利. \(n\le 5\times 10^5\). 老子懒得讲了,你们TMD对着代码自己发愣去吧. 由…
题目链接: C. Foe Pairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a permutation p of length n. Also you are given m foe pairs (ai, bi) (1 ≤ ai, bi ≤ n, ai ≠ bi). Your task…
Count Pairs You are given a prime number pp, nn integers a1,a2,…,ana1,a2,…,an, and an integer kk. Find the number of pairs of indexes (i,j)(i,j) (1≤i<j≤n1≤i<j≤n) for which (ai+aj)(a2i+a2j)≡kmodp(ai+aj)(ai2+aj2)≡kmodp. Input The first line contains i…
You are given a prime number pp, nn integers a1,a2,…,ana1,a2,…,an, and an integer kk. Find the number of pairs of indexes (i,j)(i,j) (1≤i<j≤n1≤i<j≤n) for which (ai+aj)(a2i+a2j)≡kmodp(ai+aj)(ai2+aj2)≡kmodp. Input The first line contains integers n,p,…
