feat(Go-Tool):修改单测位置,添加lomuto查找第k小元素算法代码及其单测(分治法)

This commit is contained in:
huangzj
2020-08-18 17:29:42 +08:00
parent 3f0e3b27f7
commit fa58e1a97f
27 changed files with 322 additions and 251 deletions
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/*
* @Author : huangzj
* @Time : 2020/8/18 14:11
* @DescriptionLomuto划分,找到一个数组中第k个小的元素.这边只是提供一个示例,具体类型可以根据该算法进行修改
*/
package search
//参数说明:
//list :数组
//start : 开始比较的数字下标
//end :结束比较的数字下标
//作用说明:
func partition(list []int, start int, end int) int {
moveSubscript := start
compareValue := list[start]
for i := start + 1; i <= end; i++ {
if list[i] < compareValue {
moveSubscript++
list[moveSubscript], list[i] = list[i], list[moveSubscript]
}
}
list[moveSubscript], list[start] = list[start], list[moveSubscript] //交换元素
return moveSubscript
}
func LomutoQuiteSelect(list []int, pointPosition int) int {
positionCheck(pointPosition, len(list)) //下标校验
nowPosition := partition(list, 0, len(list)-1)
//循环进行lomuto划分处理,知道找到我们需要的那个位置的元素
for nowPosition != pointPosition-1 {
if nowPosition > pointPosition-1 {
nowPosition = partition(list, 0, nowPosition)
} else {
nowPosition = partition(list, nowPosition+1, len(list)-1)
}
}
return list[nowPosition]
}
func positionCheck(pointPosition int, len int) {
if pointPosition <= 0 || pointPosition > len {
panic("查询的元素下标不能小于0,或者大于数组长度")
}
}
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/*
* @Author : huangzj
* @Time : 2020/8/18 14:54
* @Description
*/
package search
import (
"fmt"
"testing"
)
func TestPartition(t *testing.T) {
list := []int{99, 1, 2, 3, 4, 100, 200, 90, 5}
s := partition(list, 0, 9-1)
fmt.Println(fmt.Sprintf("当前第一个元素应该存在位置为:%d", s))
for _, r := range list {
fmt.Print(r, " ")
}
s = partition(list, 0, 9-1)
fmt.Println(fmt.Sprintf("当前第一个元素应该存在位置为:%d", s))
for _, r := range list {
fmt.Print(r, " ")
}
}
func TestLomutoQuiteSelect(t *testing.T) {
for k := 1; k <= 9; k++ {
s := LomutoQuiteSelect([]int{99, 1, 2, 3, 4, 100, 200, 90, 5}, k)
fmt.Println(fmt.Sprintf("当前第%d个小的元素是:%d", k, s))
fmt.Println()
}
}