From ffed6fb8226b47e1a75147be1e5b7912e75eaa32 Mon Sep 17 00:00:00 2001
From: pangzhiqiang <pangzhiqiang@xiaomi.com>
Date: Sun, 11 Oct 2020 17:17:11 +0800
Subject: [PATCH] canpartition

---
 .../algorithm/partitionequalsubsetsum.go      | 72 +++++++++++++++++++
 main.go                                       |  6 +-
 2 files changed, 75 insertions(+), 3 deletions(-)
 create mode 100644 controller/algorithm/partitionequalsubsetsum.go

diff --git a/controller/algorithm/partitionequalsubsetsum.go b/controller/algorithm/partitionequalsubsetsum.go
new file mode 100644
index 00000000..95064b91
--- /dev/null
+++ b/controller/algorithm/partitionequalsubsetsum.go
@@ -0,0 +1,72 @@
+package algorithm
+
+import "fmt"
+
+/*
+原题：https://leetcode-cn.com/problems/partition-equal-subset-sum/
+416. 分割等和子集
+给定一个只包含正整数的非空数组。是否可以将这个数组分割成两个子集，使得两个子集的元素和相等。
+
+注意:
+
+每个数组中的元素不会超过 100
+数组的大小不会超过 200
+示例 1:
+
+输入: [1, 5, 11, 5]
+
+输出: true
+
+解释: 数组可以分割成 [1, 5, 5] 和 [11].
+
+
+示例 2:
+
+输入: [1, 2, 3, 5]
+
+输出: false
+
+解释: 数组不能分割成两个元素和相等的子集.
+
+分析：
+解法一：
+使用回溯法，并且记录同一层的remain，用于剪枝
+*/
+
+func CanPartition(nums []int) bool {
+	length := len(nums)
+	if length == 0 {
+		return false
+	}
+	sum := 0
+	for i := 0; i < length; i++ {
+		sum += nums[i]
+	}
+	if sum%2 != 0 {
+		return false
+	}
+	record := make(map[int]map[int]int)
+	remain := sum / 2
+	res := doPartition(0, remain, nums, record)
+	fmt.Println(res)
+	return res
+}
+
+func doPartition(level int, remain int, nums []int, record map[int]map[int]int) bool {
+	//fmt.Println(level,remain)
+	if remain == 0 {
+		return true
+	}
+	if remain < 0 || level >= len(nums) {
+		return false
+	}
+	if _, ok := record[level][remain]; ok {
+		return false
+	}
+	if _, ok := record[level]; !ok {
+		record[level] = make(map[int]int)
+	}
+	record[level][remain] = 1
+	return doPartition(level+1, remain-nums[level], nums, record) || doPartition(level+1, remain, nums, record)
+
+}
diff --git a/main.go b/main.go
index 53c892d5..99b9add2 100644
--- a/main.go
+++ b/main.go
@@ -9,9 +9,9 @@ import (
 )
 
 func main() {
-	//nums := {}int{2}
-	tasks := []byte{'A','A','A','B','B','B'}
-	algorithm.LeastInterval(tasks,2)
+	nums := []int{100, 100, 100, 100,100,100}
+
+	algorithm.CanPartition(nums)
 	r := gin.Default()
 	InitRedis()
 	router.InitRouter(r)