http://acm.hdu.edu.cn/showproblem.php?pid=1452 因子求和

/* * 求2004^x 的素数因子的和 * n = a1 ^ p1 * a2 ^ p2 *... a3 ^ p3 * n的因子之和 sum = (a1 ^ 0 + a1 ^ 1 + ... a1 ^ p1) * (a2 ^ 0 + a2 ^ 1 + ... a2 ^ p2) * (a / b) mod m = (a % (b * m)) / b * 将2004 进行因式分解带入公式就OK * 等比数列求和　s = (an * q - a1) / (q - 1) */import java.io.*;import java.util.*;public class Main {static final int mod = 9628;public static void main(String[] args)throws IOException{StreamTokenizer cin = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));//Scanner in = new Scanner(new BufferedInputStream(System.in));int x;while(cin.nextToken() != StreamTokenizer.TT_EOF){x = (int)cin.nval;if(x == 0)break;//System.out.println(x);int ans1, ans2, ans3;ans1 = Bin(2, (2 * x + 1)) - 1; ans2 = Bin(3, (x + 1)) - 1;ans3 = Bin(167, (x + 1)) - 1;ans1 = ((ans1 * ans2) % mod) * ans3 % mod;ans1 /= (2 * 166);out.println(ans1);//System.out.println(ans1);}out.flush(); // 这个java的流要安ctrl +Ｄ　才会才缓存中取出来的}static int Bin(int a, int n){int ans = 1;while(n > 0){if(n % 2 == 1){n--;ans =(ans * a) % mod;}else{n /= 2;a = (a * a) % mod;}}return ans % mod;}} 

#include <iostream>#include <cstdio>using namespace std;int mod = 9628;int Bin(int a, int n) {int ans = 1;while (n) {if (n % 2 == 1) {n--;ans = (ans * a) % mod;} else {n /= 2;a = (a * a) % mod;}}return ans % mod;}int main() {int x;while (scanf("%d", &x) != EOF) {if (x == 0)break;int ans1, ans2, ans3;ans1 = Bin(2, (2 * x + 1)) - 1;ans2 = Bin(3, (x + 1)) - 1 ;ans3 = Bin(167, (x + 1))- 1;ans1 = ((ans1 * ans2) % mod) * ans3 % mod;ans1 /= (2 * 166);printf("%d/n", ans1);}return 0;}