刚开始看这个题目,觉得没法做.关键点是数据小于100.因此,可以枚举所有小于100的素因子进行位压缩.gcd就是求最小值,lcm就是求最大值.c++有时候超时,g++800ms.线段树可解. /* 3071 */ #include <iostream> #include <sstream> #include <string> #include <map> #include <queue> #include <set> #include…

Problem Description Give you a sequence of N(N≤100,000) integers : a1,...,an(0<ai≤1000,000,000). There are Q(Q≤100,000) queries. For each query l,r you have to calculate gcd(al,,al+1,...,ar) and count the number of pairs(l′,r′)(1≤l<r≤N)such that gcd…

首先 m = 1 时 ans = 0对于 m > 1 的 情况 由于 1 到 m-1 中所有和m互质的数字,在 对m的乘法取模 运算上形成了群 ai = ( 1<=a<m && gcd(a,m) == 1 ) 所以 对于 a 必然存在b = a^(-1) = inv(a) 使得 a * b = 1 (mod m) 这里存在两种情况 a != b 那么最后的连乘式中a b均出现一次,相乘得1 a == b 那么最后的连乘式中只出现一个a 实际上所有 a = inv(a) 的…

莫比乌斯反演简单题目. /* 1695 */ #include <iostream> #include <string> #include <map> #include <queue> #include <set> #include <stack> #include <vector> #include <deque> #include <algorithm> #include <cstdio&…

组合数学 GCD and LCM Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 451    Accepted Submission(s): 216 Problem Description Given two positive integers G and L, could you tell me how many solutions…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5194 题意:给你n个黑球,m个白球,每次从中随机抽取一个,如果抽到黑球记为1如果抽出来白球记为0,让你输出所有的可能性总数q和将这些组合中01出现的次数q,将q和p以q/p的形式输出最简形式 竟然就这样过了,只是看到了这个规律试试而已 #include<stdio.h> #include<string.h> #include<algorithm> #define MAX 1…

这种结构体排序的题,十分容易考上机题,qsort+结构体解决.马上就要机考了,多练习一下这样的题目也好. #include <stdio.h> #include <string.h> #include <stdlib.h> #define MAXNUM 100 #define NAMENUM 20 #define WIN 3 #define DRAW 1 typedef struct { char name[NAMENUM]; int in, lost; int sco…

GCD Again Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2673    Accepted Submission(s): 1123 Problem Description Do you have spent some time to think and try to solve those unsolved problem af…

Problem Description The International Clown and Pierrot Competition (ICPC), is one of the most distinguished and also the most popular events on earth in the show business. One of the unique features of this contest is the great number of judges that…

GCD Again Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2611    Accepted Submission(s): 1090 Problem Description Do you have spent some time to think and try to solve those unsolved problem a…