# Finding Pythagorean Triples

Program for finding all pythagorean triples in an array.

``````#include<iostream>
#include<vector>
#include<algorithm>
#include<math.h>

using namespace std;

int main() {

vector<int> vec = { 25, 3, 5, 4, 7, 9, 12, 13, 6, 8, 10, 15, 16, 20 };
cout << "Array : ";
for (const auto& val : vec) {
cout << val << " ";
} cout << endl;

sort(vec.begin(), vec.end());

for (int i=0; i<vec.size(); i++) {
vec[i] = vec[i] * vec[i];
}

// Check for the condition (c = a + b)
int a, b, c;
for (c = vec.size(); c > 1; c--) {
a = 0; // Start a from the beginning and keep incrementing, till it is less than b.
b = c-1; // Start b from the second last position and keep decrementing till it is > a.
while (a < b) {
if (vec[a] + vec[b] == vec[c]) {
cout << "Found : " << sqrt(vec[a]) << " " << sqrt(vec[b]) << " " << sqrt(vec[c]) << endl;
a++;
b--;
} else if (vec[a] + vec[b] < vec[c]) {
a++;
} else {
b--;
}
}
}
return 0;
}
``````

Output

``````Array : 25 3 5 4 7 9 12 13 6 8 10 15 16 20
Found : 15 20 25
Found : 12 16 20
Found : 9 12 15
Found : 5 12 13
Found : 6 8 10
Found : 3 4 5
``````