Rahul - 1 year ago 71
C Question

# Find Pythagorean triplet for which a + b + c = 1000

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.

Source: http://projecteuler.net/index.php?section=problems&id=9

I tried but didn't know where my code went wrong. Here's my code in C:

``````#include <math.h>
#include <stdio.h>
#include <conio.h>

void main()
{
int a=0, b=0, c=0;
int i;
for (a = 0; a<=1000; a++)
{
for (b = 0; b<=1000; b++)
{
for (c = 0; c<=1000; c++)
{
if ((a^(2) + b^(2) == c^(2)) && ((a+b+c) ==1000)))
printf("a=%d, b=%d, c=%d",a,b,c);
}
}
}
getch();
}
``````

``````#include <math.h>
#include <stdio.h>

int main()
{
const int sum = 1000;
int a;
for (a = 1; a <= sum/3; a++)
{
int b;
for (b = a + 1; b <= sum/2; b++)
{
int c = sum - a - b;
if ( a*a + b*b == c*c )
printf("a=%d, b=%d, c=%d\n",a,b,c);
}
}
return 0;
}
``````

explanation:

• b = a;
if a, b (a <= b)) and c are the Pythagorean triplet,
then b, a (b >= a) and c - also the solution, so we can search only one case
• c = 1000 - a -b; it's one of the conditions of the problem (don't need to scan all possible 'c': just calculate it)