GCD Again Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1997    Accepted Submission(s): 772 Problem Description Do you have spent some time to think and try to solve those unsolved problem aft…

题目大意:求小于n的gcd(i,n)大于1的个数: 题解:欧拉函数直接求gcd(i,n)==1的个数  用n减即可 #include <cstdio> int eular(int n){ int ret=1,i; for(i=2;i*i<=n;i++) if(n%i==0){ n/=i,ret*=i-1; while(n%i==0)n/=i,ret*=i; } if(n>1) ret*=n-1; return ret; } int main(){ int n; while(scan…

GCD Again Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2257    Accepted Submission(s): 908 Problem Description Do you have spent some time to think and try to solve those unsolved problem aft…

题意: 在一次acm竞赛之后,你花了一些时间去思考和尝试解决那些未解决的问题吗? 不知道?哦,当你想成为“大牛”的时候,你就必须这样做. 现在你会发现,这个问题是如此熟悉: 两个正整数a和b的最大GCD(a,b),有时是写(a,b),是a和b的最大除数,例如(,)=,(,)=.(a,b)可以很容易地找到欧几里德算法.现在,我正在考虑一个更难的问题: 给定一个整数n,请计算一个满足gcd(n,m)>1的整数m(0<m<n)的个数. 这是一个简单版本的问题“GCD”,你在最近的比赛中做了,所…

GCD Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 2742    Accepted Submission(s): 980 Problem Description Give you a sequence of N(N≤100,000) integers : a1,...,an(0<ai≤1000,000,000). There ar…

GCD is Funny 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5902 Description Alex has invented a new game for fun. There are n integers at a board and he performs the following moves repeatedly: He chooses three numbers a, b and c written at the boa…

GCD Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4272    Accepted Submission(s): 1492 Problem Description Given 5 integers: a, b, c, d, k, you're to find x in a...b, y in c...d that GCD(x, y)…

GCD 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=1695 Description Given 5 integers: a, b, c, d, k, you're to find x in a...b, y in c...d that GCD(x, y) = k. GCD(x, y) means the greatest common divisor of x and y. Since the number of choices may be…

GCD and LCM Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=4497 Description Given two positive integers G and L, could you tell me how many solutions of (x, y, z) there are, satisfying that gcd(x, y, z) = G and…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4675 题意:给出n,m,K,一个长度为n的数列A(1<=A[i]<=m).对于d(1<=d<=m),有多少个长度为n的数列B满足: (1)1<=B[i]<=m; (2)Gcd(B[1],B[2],……,B[n])=d: (3)恰有K个位置满足A[i]!=B[i]. 思路: i64 p[N]; void init(){    p[0]=1;    int i;    FOR1…