uva 10791 Minimum Sum LCM（拆分素因子）

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <stack>
#include <vector>
#include <queue>
#include <map>
#include <climits>
#include <cassert>
#define LL long long

using namespace std;
const int maxn = 1e6;
const int inf = 0x3f3f3f3f;
const double eps = 1e-8;
const double pi = 4 * atan(1.0);
const double ee = exp(1.0);

int main()
{
#ifdef LOCAL
freopen("in.txt", "r", stdin);
#endif // LOCAL
int ca = 1;
LL n;
while (scanf("%lld", &n) && n)
{
int m = sqrt(n);
LL ans = 0;
LL cnt = 0;
for (int i = 2; i <= m; i++)
{
if (n % i == 0)
{
cnt++;
LL t = 1;
while (n % i == 0)
{
t *= i;
n /= i;
}
ans += t;
}
}
if (cnt == 0)///素数 因子和为本身+1
{
ans = n + 1;
}
else if (cnt == 1 || 1 < n)///单因子或拆完所有数留下了1个大于n的素数
{
ans += n;
}
printf("Case %d: %lld\n", ca++, ans);
}
return 0;
}