From 653d645dabd54c9b2d94afc27dc3cb308f82b519 Mon Sep 17 00:00:00 2001
From: Younglesszzz <571688981@qq.com>
Date: Sat, 29 Jan 2022 13:29:28 +0800
Subject: [PATCH 1/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E4=BA=86=E4=BA=8C?=
 =?UTF-8?q?=E7=BB=B4=E6=95=B0=E7=BB=84=E7=89=88=E6=9C=AC=EF=BC=8C=E7=9B=B8?=
 =?UTF-8?q?=E6=AF=94=E4=BA=8E=E4=B8=80=E7=BB=B4=E5=A5=BD=E7=90=86=E8=A7=A3?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../1049.最后一块石头的重量II.md     | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/problems/1049.最后一块石头的重量II.md b/problems/1049.最后一块石头的重量II.md
index d64e7e56..7b67b1ac 100644
--- a/problems/1049.最后一块石头的重量II.md
+++ b/problems/1049.最后一块石头的重量II.md
@@ -153,6 +153,8 @@ public:
 
 
 Java：
+
+一维数组版本
 ```Java
 class Solution {
     public int lastStoneWeightII(int[] stones) {
@@ -173,6 +175,41 @@ class Solution {
         return sum - 2 * dp[target];
     }
 }
+```
+二维数组版本（便于理解）
+```Java
+class Solution {
+    public int lastStoneWeightII(int[] stones) {
+        int sum = 0;
+        for (int s : stones) {
+            sum += s;
+        }
+
+        int target = sum / 2;
+        //初始化，dp[i][j]为可以放0-i物品，背包容量为j的情况下背包中的最大价值
+        int[][] dp = new int[stones.length][target + 1];
+        //dp[i][0]默认初始化为0
+        //dp[0][j]取决于stones[0]
+        for (int j = stones[0]; j <= target; j++) {
+            dp[0][j] = stones[0];
+        }
+
+        for (int i = 1; i < stones.length; i++) {
+            for (int j = 1; j <= target; j++) {//注意是等于
+                if (j >= stones[i]) {
+                    //不放:dp[i - 1][j] 放:dp[i - 1][j - stones[i]] + stones[i]
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - stones[i]] + stones[i]);
+                } else {
+                    dp[i][j] = dp[i - 1][j];
+                }
+            }
+        }
+
+        System.out.println(dp[stones.length - 1][target]);
+        return (sum - dp[stones.length - 1][target]) - dp[stones.length - 1][target];
+    }
+}
+
 ```
 
 Python：

From b1c3d5c4f9db71676ebc44f9c41a10778dfea1c5 Mon Sep 17 00:00:00 2001
From: Younglesszzz <571688981@qq.com>
Date: Sat, 29 Jan 2022 13:39:27 +0800
Subject: [PATCH 2/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E4=BA=86=E4=BA=8C?=
 =?UTF-8?q?=E7=BB=B4=E6=95=B0=E7=BB=84=E7=89=88=E6=9C=AC=EF=BC=8C=E7=9B=B8?=
 =?UTF-8?q?=E6=AF=94=E4=BA=8E=E4=B8=80=E7=BB=B4=E5=A5=BD=E7=90=86=E8=A7=A3?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0416.分割等和子集.md | 39 +++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/problems/0416.分割等和子集.md b/problems/0416.分割等和子集.md
index 45b8b416..9da1f8d5 100644
--- a/problems/0416.分割等和子集.md
+++ b/problems/0416.分割等和子集.md
@@ -210,6 +210,45 @@ class Solution {
 }
 ```
 
+二维数组版本（易于理解）：
+```Java
+class Solution {
+    public boolean canPartition(int[] nums) {
+        int sum = 0;
+        for (int i = 0; i < nums.length; i++) {
+            sum += nums[i];
+        }
+
+        if (sum % 2 == 1)
+            return false;
+        int target = sum / 2;
+
+        //dp[i][j]代表可装物品为0-i，背包容量为j的情况下，背包内容量的最大价值
+        int[][] dp = new int[nums.length][target + 1];
+
+        //初始化,dp[0][j]的最大价值nums[0](if j > weight[i])
+        //dp[i][0]均为0，不用初始化
+        for (int j = nums[0]; j <= target; j++) {
+            dp[0][j] = nums[0];
+        }
+
+        //遍历物品，遍历背包
+        //递推公式:
+        for (int i = 1; i < nums.length; i++) {
+            for (int j = 0; j <= target; j++) {
+                //背包容量可以容纳nums[i]
+                if (j >= nums[i]) {
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - nums[i]] + nums[i]);
+                } else {
+                    dp[i][j] = dp[i - 1][j];
+                }
+            }
+        }
+
+        return dp[nums.length - 1][target] == target;
+    }
+}
+```
 Python：
 ```python
 class Solution: