例题7-3 分数拆分 UVa10976

1.题目描述：点击打开链接

2.解题思路：根据题目描述，可以解出来y的范围是1≤y≤2k。进而可以求出x=ky/(y-n)。注意x要大于0且是整数。

3.代码：

#define _CRT_SECURE_NO_WARNINGS 
#include<iostream>
#include<algorithm>
#include<string>
#include<sstream>
#include<set>
#include<vector>
#include<stack>
#include<map>
#include<queue>
#include<deque>
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<ctime>
#include<functional>
using namespace std;
#define N 50000
int u[N], v[N];
int main()
{
	//freopen("t.txt", "r", stdin);
	int n;
	while (~scanf("%d", &n))
	{
		int cnt = 0;
		int len = 2 * n;
		for (int y = 1; y <= len; y++)
		{
			if (y - n > 0 && n*y % (y - n) == 0)
			{
				int x = n*y / (y - n);
				u[cnt] = x, v[cnt++] = y;
			}
		}
		printf("%d\n", cnt);
		for (int i = 0; i < cnt; i++)
			printf("1/%d = 1/%d + 1/%d\n", n, u[i], v[i]);
	}
	return 0;
}