diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md
index 8122240e..c15d1ac1 100644
--- a/problems/0383.赎金信.md
+++ b/problems/0383.赎金信.md
@@ -88,7 +88,7 @@ public:
             return false;
         }
         for (int i = 0; i < magazine.length(); i++) {
-            // 通过recode数据记录 magazine里各个字符出现次数
+            // 通过record数据记录 magazine里各个字符出现次数
             record[magazine[i]-'a'] ++;
         }
         for (int j = 0; j < ransomNote.length(); j++) {
@@ -219,7 +219,7 @@ class Solution:
 ```go
 func canConstruct(ransomNote string, magazine string) bool {
     record := make([]int, 26)
-    for _, v := range magazine {   // 通过recode数据记录 magazine里各个字符出现次数
+    for _, v := range magazine {   // 通过record数据记录 magazine里各个字符出现次数
         record[v-'a']++
     }
     for _, v := range ransomNote { // 遍历ransomNote，在record里对应的字符个数做--操作
diff --git a/problems/0714.买卖股票的最佳时机含手续费（动态规划）.md b/problems/0714.买卖股票的最佳时机含手续费（动态规划）.md
index 1443f147..042de947 100644
--- a/problems/0714.买卖股票的最佳时机含手续费（动态规划）.md
+++ b/problems/0714.买卖股票的最佳时机含手续费（动态规划）.md
@@ -270,18 +270,29 @@ impl Solution {
 **动态规划**
 ```Rust
 impl Solution {
-    fn max(a: i32, b: i32) -> i32 {
-        if a > b { a } else { b }
-    }
     pub fn max_profit(prices: Vec<i32>, fee: i32) -> i32 {
-        let n = prices.len();
-        let mut dp = vec![vec![0; 2]; n];
-        dp[0][0] -= prices[0];
-        for i in 1..n {
-            dp[i][0] = Self::max(dp[i - 1][0], dp[i - 1][1] - prices[i]);
-            dp[i][1] = Self::max(dp[i - 1][1], dp[i - 1][0] + prices[i] - fee);
+        let mut dp = vec![vec![0; 2]; prices.len()];
+        dp[0][0] = -prices[0];
+        for (i, &p) in prices.iter().enumerate().skip(1) {
+            dp[i][0] = dp[i - 1][0].max(dp[i - 1][1] - p);
+            dp[i][1] = dp[i - 1][1].max(dp[i - 1][0] + p - fee);
         }
-        Self::max(dp[n - 1][0], dp[n - 1][1])
+        dp[prices.len() - 1][1]
+    }
+}
+```
+
+**动态规划空间优化**
+
+```rust
+impl Solution {
+    pub fn max_profit(prices: Vec<i32>, fee: i32) -> i32 {
+        let (mut low, mut res) = (-prices[0], 0);
+        for p in prices {
+            low = low.max(res - p);
+            res = res.max(p + low - fee);
+        }
+        res
     }
 }
 ```
diff --git a/problems/1221.分割平衡字符串.md b/problems/1221.分割平衡字符串.md
index b587514a..2a7b0922 100644
--- a/problems/1221.分割平衡字符串.md
+++ b/problems/1221.分割平衡字符串.md
@@ -156,6 +156,21 @@ var balancedStringSplit = function(s) {
 };
 ```
 
+### TypeScript
+
+```ts
+function balancedStringSplit(s: string): number {
+    let count: number = 0
+    let res: number = 0
+    for(let i of s){
+        if(i === 'R') count++
+        else count--
+        if(count === 0) res++
+    }
+
+    return res
+};
+```
 
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