Golang語言常用算法

在學習golang語言，文檔看的實在是乏味，就想着把常用的算法做個實現，邊寫變學習，想來效果還是不錯的！

1. 堆排序

package main

import "fmt"
func buildHeap(array []int, length int) {
	var i, j int;
	for i = 1; i < length; i = i + 1 {
		for j = i; j > 0 && array[j] > array[(j-1)/2]; j = (j - 1)/2  {
			array[j], array[(j-1)/2] = array[(j-1)/2], array[j]  
		}
	}
}
func heapSort(array []int, length int) {
	array[0], array[length - 1] = array[length - 1], array[0]
	if length <= 2 {
		return
	}
	i, j:= 0, 0
	for  {
		j = 2 * i + 1
		if j + 1 < length - 1 {
			if array[j] < array[j + 1] {
				j = j + 1
			}
		} else if j >= length -1 {
			break
		}	
		array[i], array[j] = array[j], array[i]
		i = j
	}
	heapSort(array, length - 1)
}
func main() {
	primes := [6]int{3, 11, 5, 2, 13, 7}
	fmt.Println("orginal", primes)
	buildHeap(primes[:], len(primes))
	fmt.Println("Max heap", primes)
	heapSort(primes[:], len(primes))
	fmt.Println("after sorting", primes)
}

2. 輸出fibanocci列數

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	first, second := 0, 1
	var out int
	return func() int {
		out, first = first, second
		second = out + first
		return out
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}

3.