GCD SUM Time Limit: 8000/4000MS (Java/Others)Memory Limit: 128000/64000KB (Java/Others) SubmitStatisticNext Problem Problem Description 给出N,M执行如下程序:long long  ans = 0,ansx = 0,ansy = 0;for(int i = 1; i <= N; i ++)   for(int j = 1; j <= M; j ++)     …

GCD Time Limit: / MS (Java/Others) Memory Limit: / K (Java/Others) Total Submission(s): Accepted Submission(s): Problem Description Given 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…

题意:求(1,b)区间和(1,d)区间里面gcd(x, y) = k的数的对数(1<=x<=b , 1<= y <= d). 知识点: 莫比乌斯反演/*12*/ 线性筛求莫比乌斯反演函数: void Init() { memset(vis,0,sizeof(vis)); mu[1] = 1; cnt = 0; for(int i=2; i<N; i++) { if(!vis[i]) { prime[cnt++] = i; mu[i] = -1; } for(int j=0;…

gcd就是欧几里得算法,可以快速的求出俩个数的最大公因数,进而也可以求其最大公倍数(俩数之积除以最大公因数),比较简单直接看代码就好了,一般用递归版,简短精简,敲得快,但如果数剧奇葩,怕溢出,那就用递推版的. 递归版: int gcd(int a,int b) {   if(b==0) return a; return gcd(b,a%b); } 递推版: int gcd(int a,int b) {    int r=a%b while(r>0) {   a=b; b=r; r=a%b; }…

GCD Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4291    Accepted Submission(s): 1502 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 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)…

F - GCD Time Limit:3000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 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 c…

题目传送门 /* 数学:官方题解 首先,数组中每个元素至少是1 然后对于任意一个询问Li, Ri, Ansi, 说明Li ~ Ri中的元素必定是Ansi的倍数,那么只需将其与Ansi取最小公倍数即可 如果在计算过程中有一个值超出了可行范围,那么就无解了 在计算完成之后,注意这个解并不一定是正确的,还需要对于所有询问检查一遍 时间复杂度O(NQlogX), X为值的范围 题目不难,算是签到题,可是队友考虑复杂了,GCD (0, ..) ?! 反思:题目要读仔细,组队时做不来要让队友帮忙读题想题 *…

1 n d v相当于给$a[x]+=v[\gcd(x,n)=d]$ \[\begin{eqnarray*}&&v[\gcd(x,n)=d]\\&=&v[\gcd(\frac{x}{d},\frac{n}{d})=1]\\&=&v\sum_{k|\gcd(\frac{x}{d},\frac{n}{d})}\mu(k)\\&=&\sum_{k|\frac{n}{d},dk|x}v\mu(k)\end{eqnarray*}\] 设$a[i]=\su…

GCD Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 6081    Accepted Submission(s): 2223 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)…