题解 The k-th prime number 试读

//完全照搬筛法代码,输出prime[k-1]即可
#include <cstdio>
#include <iostream>
#include <vector>
using namespace std;
const int maxn = 1e5 + 10;
bool isprime[maxn];
vector<int>prime;
void initial() {
	for (int i = 0; i < maxn; i++) {
		isprime[i] = true;
	}
	isprime[0] = false;
	isprime[1] = false;
	for (int i = 2; i < maxn; i++) {
		if (!isprime[i]) {
			continue;
		}
		prime.push_back(i);
		for (int j = i * i; j < maxn; j += i) {
			isprime[j] = false;
		}
	}
}
int main() {

	initial();

	int k;
	while (scanf("%d", &k)!=EOF) {
		printf("%d\n", prime[k - 1]);
	}

	return 0;
}