zoukankan      html  css  js  c++  java
  • LightOJ

    Find the result of the following code:


    long long pairsFormLCM( int n ) {
        long long res = 0;
        for( int i = 1; i <= n; i++ )
            for( int j = i; j <= n; j++ )
               if( lcm(i, j) == n ) res++; // lcm means least common multiple
        return res;
    }


    A straight forward implementation of the code may time out. If you analyze the code, you will find that the code actually counts the number of pairs (i, j) for which lcm(i, j) = n and (i ≤ j).


    Input
    Input starts with an integer T (≤ 200), denoting the number of test cases.


    Each case starts with a line containing an integer n (1 ≤ n ≤ 1014).


    Output
    For each case, print the case number and the value returned by the function 'pairsFormLCM(n)'.


    Sample Input
    15
    2
    3
    4
    6
    8
    10
    12
    15
    18
    20
    21
    24
    25
    27
    29
    Sample Output
    Case 1: 2
    Case 2: 2
    Case 3: 3
    Case 4: 5
    Case 5: 4
    Case 6: 5
    Case 7: 8
    Case 8: 5
    Case 9: 8
    Case 10: 8
    Case 11: 5
    Case 12: 11
    Case 13: 3
    Case 14: 4

    Case 15: 2

    求小于等于n的数中最小公倍数等于N的组合而且 i<=j  ;

    #include<stack>
    #include<queue>
    #include<math.h>
    #include<vector>
    #include<string>
    #include<stdio.h>
    #include<map>
    #include<iostream>
    #include<string.h>
    #include<algorithm>
    #define maxn 1000005
    #define maxm 10000005
    #define MAXN 100005
    #define MAXM 10005
    #define mem(a,b) memset(a,b,sizeof(a))
    #define ll unsigned long long
    #define inf 0x3f3f3f3f
    using namespace std;
    bool vis[maxm+5];
    ll tot;
    ll p[maxn];
    void get_prime(){
         tot=0;
        mem(vis,true);
        for(ll i=2;i<=maxm;i++){
            if(vis[i]){
                p[tot++]=i;
                for(ll j=i*i;j<=maxm;j+=i)vis[j]=false;
            }
        }
    }
    ll f(ll n){
        if(n==1)return 1;
        ll ans=1;
        for(int i=0;i<tot;i++){
            if(n%p[i]==0){
                ll x=0;
               while(n%p[i]==0){x++;n/=p[i];}
                ans*=(2*x+1);
            }
        }
        if(n!=1)ans*=(2*1+1);
        return ans/2+1;
    }
    int main(){
        get_prime();
        int t,test=0;
        scanf("%d",&t);
        while(t--){
        ll n;
        scanf("%lld",&n);
       printf("Case %d: %lld
    ",++test,f(n));
        }
    }
    

  • 相关阅读:
    对象属性键值[key]属性问题
    理解 JavaScript 中的 for…of 循环
    vue初学篇----过滤器(filters)
    CSS变量
    SCSS !default默认变量
    vue 集成 NEditor 富文本
    如何在Github上面精准搜索开源项目?
    OSS介绍
    键盘各键对应的编码值(key code)
    网易云音乐歌单生成外链播放器
  • 原文地址:https://www.cnblogs.com/da-mei/p/9053225.html
Copyright © 2011-2022 走看看