From 90575b67454b67808dd35ef75f16f1a6f1f30c4b Mon Sep 17 00:00:00 2001
From: ShusenTang <tangshusen@pku.edu.cn>
Date: Mon, 25 Nov 2019 23:26:57 +0800
Subject: [PATCH] add solution2

---
 solutions/416. Partition Equal Subset Sum.md | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/solutions/416. Partition Equal Subset Sum.md b/solutions/416. Partition Equal Subset Sum.md
index e7d81cf..855a4d4 100644
--- a/solutions/416. Partition Equal Subset Sum.md	
+++ b/solutions/416. Partition Equal Subset Sum.md	
@@ -13,7 +13,7 @@
 
 
 ## 思路二
-其实本题也可以看做是一个01背包问题，改天对背包问题做个总结，先占个坑。
+其实本题也可以看做是一个恰好装满的01背包问题，我在我的博客文章[动态规划之背包问题系列](https://tangshusen.me/2019/11/24/knapsack-problem/)对常见的几类背包问题做了个总结，此题的分析见5.1节，这里只给出代码。
 
 
 # C++
@@ -30,3 +30,21 @@ public:
     }
 };
 ```
+
+## 思路二
+``` C++
+bool canPartition(vector<int>& nums) {
+    int sum = 0, n = nums.size();
+    for(int &num: nums) sum += num;
+    if(sum % 2) return false;
+    
+    int capacity = sum / 2;
+    vector<bool>dp(capacity + 1, false);
+    dp[0] = true;
+    for(int i = 1; i <= n; i++)
+        for(int j = capacity; j >= nums[i-1]; j--)
+            dp[j] = dp[j] || dp[j - nums[i-1]];
+        
+    return dp[capacity];
+}
+```