题目链接:https://cn.vjudge.net/problem/CodeForces-546D 题意 抱歉,我给忘了,现在看题目又看不懂: P 思路 筛法+dp 话说这个函数应该是积性函数,然后就想到了动态规划优化筛法. 提交过程 AC 代码 #include <cstdio> #include <cstring> const int maxp=1e6, maxn=5e6+20; int primes[maxn], psize; long long ans[maxn], pr…

题目链接 这个题, 告诉你a, b的值, 那么只需要求出b到a之间的数, 每个数有多少个因子就可以. 具体看代码, 代码里面有解释 #include<bits/stdc++.h> using namespace std; #define pb(x) push_back(x) ; int p[maxn], c[maxn]; int main() { memset(p, , sizeof(p)); memset(c, , sizeof(c)); ; i<=maxn; i++) { if(!p…

题目:戳我这个题与HDUOJ 5317有异曲同工之妙 题意:题意看懂了上面的一大串英文之后其实很简单,就是给你一个正整数n,问你n有多少个质因子,不过这里n是通过a!/b!给定的,也就是说n=(a!/b!); 分析:由于这里1 ≤ b ≤ a ≤ 5 000 000,数据很大,所以简单暴力一定超时,具体看代码. #include <iostream> #include <cstdio> using namespace std; ; int t; //测试组数 }; //打表,将n的…

类似筛素数的方法……求出前缀和.然后直接O(1)回答即可. #include <bits/stdc++.h> using namespace std; #define rep(i,a,b) for(int i(a); i <= (b); ++i) + ; int num[N]; bool p[N]; int T, n, m; int main(){ memset(p, true, sizeof p); memset(num, , sizeof num); p[] = false; rep…

题目描述: Soldier and Number Game time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Two soldiers are playing a game. At the beginning first of them chooses a positive integer n and gives it to t…

题目传送门 /* 题意:b+1,b+2,...,a 所有数的素数个数和 DP+埃氏筛法:dp[i] 记录i的素数个数和,若i是素数,则为1:否则它可以从一个数乘以素数递推过来 最后改为i之前所有素数个数和,那么ans = dp[a] - dp[b]: 详细解释:http://blog.csdn.net/catglory/article/details/45932593 */ #include <cstdio> #include <algorithm> #include <cs…

D. Soldier and Number Game Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/546/problem/D Description Two soldiers are playing a game. At the beginning first of them chooses a positive integer n and gives it to the second s…

题目传送门 /* 题意:这题就是求b+1到a的因子个数和. 数学+DP:a[i]保存i的最小因子,dp[i] = dp[i/a[i]] +1;再来一个前缀和 */ /************************************************ Author :Running_Time Created Time :2015-8-1 14:08:34 File Name :B.cpp ************************************************…

D. Soldier and Number Game time limit per test3 seconds memory limit per test256 megabytes inputstandard input outputstandard output Two soldiers are playing a game. At the beginning first of them chooses a positive integer n and gives it to the seco…

D. Soldier and Number Game time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Two soldiers are playing a game. At the beginning first of them chooses a positive integer n and gives it to the…