HDU 4345 Permutation dp

#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <memory.h>
#include <cassert>
using namespace std;
typedef long long ll;
const int N = 185;
const int M = 1000 + 1;
bool pri(int x) {
	if (x == 2)
		return true;
	else if (x%2==0)
		return false;
	for (int i = 3; i * i <= x; i += 2)
		if (x%i==0)
			return false;
	return true;
}
int prime[N], idx = 0;
ll ans[M], d[N][M];
int main() {
	int v;
	ll sum;
	for (int i = 2; i <= 1000; ++i)
		if (pri(i))
			prime[idx++] = i;
	memset(d, 0, sizeof d);
	d[0][0] = 1;
	for (int i = 0; i < idx; ++i) {
		v = prime[i];
		while (v < M) {
			for (int j = v; j < M; ++j)
				d[i+1][j] += d[i][j - v];
			v = v * prime[i];
		}
		for (int j = 0; j < M; ++j)
			d[i+1][j] += d[i][j];
	}
			
	ans[0] = d[idx][0];
	for (int i = 1; i < M; ++i)
			ans[i] = ans[i - 1] + d[idx][i];
	ans[0] = 0;
	int n;
	while (~scanf("%d", &n)) {
		printf("%I64d
", ans[n]);
	}
	return 0;
}