From 03028b1a41567b2a9bfa1f4c4f8d4d5e6cc4264c Mon Sep 17 00:00:00 2001
From: kercylan98 <kercylan@gmail.com>
Date: Sat, 29 Jul 2023 17:13:12 +0800
Subject: [PATCH] =?UTF-8?q?perf:=20=E4=BC=98=E5=8C=96=20slice.Combinations?=
 =?UTF-8?q?=20=E6=95=88=E7=8E=87?=
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---
 utils/slice/slice.go | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/utils/slice/slice.go b/utils/slice/slice.go
index 756f458..70d6e12 100644
--- a/utils/slice/slice.go
+++ b/utils/slice/slice.go
@@ -1,7 +1,6 @@
 package slice
 
 import (
-	"fmt"
 	"math/rand"
 	"reflect"
 )
@@ -221,27 +220,13 @@ func GetIndexAny[V any](slice []V, values V) int {
 
 // Combinations 获取给定数组的所有组合，包括重复元素的组合
 func Combinations[T any](a []T) [][]T {
-	n := len(a)
-
-	// 去除重复元素，保留唯一元素
-	uniqueSet := make(map[string]bool)
-	uniqueSlice := make([]T, 0, n)
-	for _, val := range a {
-		ptr := fmt.Sprintf("%p", val)
-		if !uniqueSet[ptr] {
-			uniqueSet[ptr] = true
-			uniqueSlice = append(uniqueSlice, val)
-		}
-	}
-
-	n = len(uniqueSlice)        // 去重后的数组长度
-	totalCombinations := 1 << n // 2的n次方
 	var result [][]T
-	for i := 0; i < totalCombinations; i++ {
+	n := len(a)
+	for i := 0; i < (1 << n); i++ {
 		var currentCombination []T
 		for j := 0; j < n; j++ {
 			if (i & (1 << j)) != 0 {
-				currentCombination = append(currentCombination, uniqueSlice[j])
+				currentCombination = append(currentCombination, a[j])
 			}
 		}
 		result = append(result, currentCombination)