问题:求这样的四个自然数p,q,r,s(p<=q<=r<=s),使得等式1/p + 1/q +1/r +1/s=1成立,
C#趣味程序分数之和
。 分析:将原式同分,化简整理后得到:2<=p<5,p<=q<7,q
using System;namespace ConsoleApplication1{ class Program { static void Main(string[] args) { int p, q, r, s, n = 0; for (p = 2; p < 5; p++) for (q = p; q < 7; q++) for (r = q; r < 13; r++) if (p * q * r - q * r - p * r - p * q != 0) { s = (p * q * r) / (p * q * r - q * r - p * r - p * q); if ((p * q * r)%(p * q * r - q * r - p * r - p * q)==0 && s >= r) Console.WriteLine([{0}]:1/{1}+1/{2}+1/{3}+1/{4}=1 + '',string.Format({0,2},++n),p,q,r,s); } } }}