euler10.go

package main

import (
  "fmt"
	"math"
)

func nextPrime() func() int {
	last := 3
	return func() int {
		for isprime(last) == false {
			last = last + 2
		}
		prime := last
		last = last + 2
		return prime
	}
}

func isprime(x int) bool {
	var i float64
	for i = 3; i <= math.Sqrt(float64(x)); i += 2 {
		if math.Mod(float64(x), float64(i)) == 0 {
			return false
		}
	}
	return true
}

func main() {
	var total int64 = 2
	pg := nextPrime()
	num := pg()
	for num < 2000000 {
		total = total + int64(num)
		num = pg()
	}
	fmt.Println(total)
}

euler10.py

def primgen(maximum=2000000):
    yield 2
    yield 3
    yield 5
    yield 7
    x = 9
    while x < maximum:
        if isprime(x):
            yield x
        x += 2


def isprime(n):
    if n == 2:
        return 1
    if n % 2 == 0:
        return 0
    max = n ** 0.5 + 1
    i = 3

    while i <= max:
        if n % i == 0:
            return False
        i += 2
    return True

if __name__ == "__main__":
    primes = [x for x in primgen()]
    print len(primes), sum(primes)

euler9.go

package main

import (
  "errors"
	"fmt"
)

func makeTriple(m, n int) (a, b, c int, err error) {
	if m > n {
		err := errors.New("m must be less than n")
		return 0, 0, 0, err
	}
	a = n*n - m*m
	b = 2 * n * m
	c = n*n + m*m
	return a, b, c, nil
}

func main() {
	done := false
	m, n := 1, 2
	for done == false {
		a, b, c, err := makeTriple(m, n)
		if err != nil {
			panic(err)
		}
		if a+b+c == 1000 {
			fmt.Println(a * b * c)
			done = true
		} else {
			n = n + 1
		}
		if a+b+c > 1000 {
			m = m + 1
			n = m + 2
		}
	}
}

euler9.py

def make_triple(m, n):
    assert(m < n)
    a = n * n - m * m
    b = 2 * n * m
    c = n * n + m * m
    return a, b, c


def main():
    done = False
    m, n = 1, 2
    while not done:
        a, b, c = make_triple(m, n)
        if a + b + c == 1000:
            print(a * b * c)
            done = True
        else:
            n = n + 1
        if a + b + c > 1000:
            m = m + 1
            n = m + 2


if __name__ == "__main__":
    main()