[Project Euler]加入歐拉 Problem 9

A Pythagorean triplet is a set of three natural numbers, a b c, for which,

a2 + b2 = c2

For example, 32 + 42 = 9 + 16 = 25 = 52.

There exists exactly one Pythagorean triplet for which a + b + c = 1000.
Find the product abc.

 

 

意思很明白找出這樣的a, b, c

a+b+c = 1000

a <  b < c

a*a + b*b = c*c

歐拉項目第九題#include <stdio.h>#include <stdlib.h>int main(int argc, char *argv[]){    int a, b, c;    double product;        for(a = 1; a < 500; a++) //這裡可以大致給a,b,c 確定下範圍，減少迴圈次數       for(b = 1; b < 500; b++)        for(c = 300; c < 1000; c++)         {            if((a + b + c ==1000) && (a * a + b * b == c * c))            {                if(a < b)                {                    double product = a*b*c;                    printf("%lf", product);                }            }        }    system("PAUSE");  return 0;}