The Roberto Selbach Chronicles

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Euler 9 in Go

This was surprising to me. For fun I picked one of the Euler algorithms I played with in the past and rewrote it in Go. The idea was to rewrite it idiomatically to see how different things might look. Nothing else. The very first thing I did was to get the exact algorithm and rewrite, no idiomatic changes.

package main

import "fmt"

func isTriplet(a, b, c int) bool {
return a * a + b * b == c * c

func main() {
for a := 1; a < 1000; a++ {
for b := a + 1; b < (1000 – a) / 2; b++ {
c := 1000 – a – b
if isTriplet(a, b, c) {
fmt.Println(a * b * c)


What surprised me is that this thing runs in 0.005s, which is faster than the Python implementation and very close to the one in C. It surprised me because this wasn’t really supposed to happen. The Go compiler isn’t well optimized, especially compared to compilers with a many-years headstart.