HDU - 4952 Number Transformation

2520 10
2520 20
0 0

Case #1: 2520
Case #2: 2600
题意：给你个x，k次操作，对于第i次操作是：要找个nx,使得nx是>=x的最小值，且能整除i，求k次操作后的数

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
typedef __int64 ll;
using namespace std;

ll x, k;

int main() {
	int cas = 1;
	while (scanf("%I64d%I64d", &x, &k) != EOF && x+k) {
		ll tmp = x;
		for (ll i = 2; i <= k; i++) {
			tmp = tmp - tmp/i;
			if (tmp < i)
				break;
		}
		printf("Case #%d: %I64d\n", cas++, tmp*k);
	}
	return 0;
}