UVa11728

解題心得

暴力解

程式碼

#include <iostream>
using namespace std;

int factor_sum(int n)
{
	int sum = 0;
	
	for (int i = 1; i <= n; i++)
	{
		if (n % i == 0)
			sum += i;
	}
	return sum;
}

int main()
{
	int S, count = 1;
	while (cin >> S)
	{
		if (S == 0) break;
		cout << "Case " << count++ << ": ";

		int ans = -1;
		for (int i = 1; i < S; i++)
		{
			if (factor_sum(i) == S)
			{
				ans = i;
			}
		}
		if (S == 1)
			ans = 1;
		cout << ans << endl;
	}
	return 0;
}