carloscn
commented
1 year ago Analysis
// 1 2 3 4 5 6 7 8 9 10
// 1 2 10 / 1 2 9 / 1 2 8 / 1 2 7 / 1 2 6 / 1 2 5 / 1 2 4 / 1 2 3
// 1 3 10 / 1 3 9 / ... / 1 3 4
// 1 4 10 / 1 4 9 / ... / 1 4 5
// 2 3 10 / 2 3 9
// ...
// ...
pub fn count_triples(n: i32) -> i32
{
if n < 3 {
return 0;
}
let mut ret:i32 = 0;
for i in 1..n + 1 {
for j in (i + 1)..n + 1 {
for k in (j + 1)..n + 1{
if i * i + j * j == k * k {
ret += 2;
}
}
}
}
return ret;
}
Description
A square triple (a,b,c) is a triple where a, b, and c are integers and a2 + b2 = c2.
Given an integer n, return the number of square triples such that 1 <= a, b, c <= n.
Example 1:
Input: n = 5 Output: 2 Explanation: The square triples are (3,4,5) and (4,3,5).
Example 2:
Input: n = 10 Output: 4 Explanation: The square triples are (3,4,5), (4,3,5), (6,8,10), and (8,6,10).
Constraints:
1 <= n <= 250