Huangzj
57 lines
1.0 KiB
Go
57 lines
1.0 KiB
Go
/*
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* @Author : huangzj
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* @Time : 2021/3/22 15:29
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* @Description：
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*/
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package FullPermutation
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import (
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sort2 "Go-Tool/util/sort"
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)
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//字典序获取全排列
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func (per *Permutation) DictionaryOrder(b []byte) {
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//先排序
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sort2.QuickSortByte(b, 0, len(b)-1)
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for {
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bef := 0
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afr := 0
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result := make([]byte, len(b))
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copy(result, b)
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per.bytes = append(per.bytes, result)
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//从右往左找到第一个左边比右边小的数字
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for bef = len(b) - 2; ; bef-- {
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if bef < 0 {
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return
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}
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if b[bef] < b[bef+1] {
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break
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}
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}
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//知道q的位置之后
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//从q开始向右边查找比位置q的数字大的第一个数字的位置
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for afr = len(b) - 1; afr > 0; afr-- {
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if b[afr] > b[bef] {
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break
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}
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}
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//交换两个数字
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b[bef], b[afr] = b[afr], b[bef]
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//把后面的数字进行转置成递增顺序
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b = per.Reverse(b, bef+1, len(b)-1)
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}
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}
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func (per *Permutation) Reverse(b []byte, start, end int) []byte {
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for start <= end {
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b[start], b[end] = b[end], b[start]
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start++
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end--
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}
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return b
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}
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