c++ - Pythagorean triplets whose sum is 1000? -

project euler problem 9. tried solve it, infact triplets not pythagorean triplets , sum 1000, why? made sure pythagorean triplets. here long , not optimized code:

#include <iostream> #include <math.h>  using namespace std;  int main() {     int a,b,c; //decalring triplets...     a=1; //first triplet starts 3     b=1;     int c2;//c square      while(true)     {         for(b=1;b<a;b++){         c2 = a*a+b*b;         c = sqrt(c2);         if(c*c == c2 && a+b+c==1000)         {             cout<<a<<","<<b<<","<<c<<"\n";         }         a++;         }         b++;     } } 

final working code:

#include <iostream> #include <math.h>  using namespace std;  int main() {     int x,y,z,a;     for(x=1;x<=1000;x++)     {         for(y=1;y<=1000;y++)         {             = x*x+y*y;             z=sqrt(a);             if(z*z==a && x+y+z==1000 && x<y){             cout<<x<<","<<y<<","<<z<<"."<<"\n";             cout<<"so product of of 3 triplets "<<x*y*z;             }         }     }     return 0; } 

your loop conditions off. c corresponding current a , b computed inside loop. therefore, cannot test loop iteration on value of c because it's old one. remove c conditions, put test integrality of sqrt(c2), , have solution.

edit

you seem trying results doing more or less random code changes. not going ot anywhere.

start formulating algorithm in plain human language. re-word (still plain human language) structure matching c++ code concepts. code concepts.

something this:

step 1. in pythagorean triplet, third member c determined first two. examine possible values of a , b, , if form pythagorean triplet, test sum of 1000.

step 2. each a, test bs larger a such a + b less 1000. compute c2 , see if it's square. if so, test sum of triplet.

step 3.

#include <cmath> #include <iostream>  int main() {   (int = 3; < 1000; ++a) {     (int b = + 1; + b < 1000; ++b) {       int c2 = * + b * b;       int c = std::sqrt(c2);       if (c * c == c2) {         if (a + b + c == 1000) {           std::cout << "found triplet " << << ", " << b << ", " << c << '\n';         }       }     }   } }