leetcode update

content/posts/leetcode.md

@@ -877,3 +877,52 @@ func intersection(nums1 []int, nums2 []int) []int {
     return res
 }
 ```
+
+## day14 2024-03-11
+
+### 791. Custom Sort String
+
+You are given two strings order and s. All the characters of order are unique and were sorted in some custom order previously.
+
+Permute the characters of s so that they match the order that order was sorted. More specifically, if a character x occurs before a character y in order, then x should occur before y in the permuted string.
+
+Return any permutation of s that satisfies this property.
+
+![0311fLXVhVrYfXgA](https://testingcf.jsdelivr.net/gh/game-loader/picbase@master/uPic/0311fLXVhVrYfXgA.png)
+
+### 题解
+
+本题初始想先扫描s字符串, 使用一个map记录字符串中各个字符的数量, 再遍历order依次将字符按数量附加到末尾即可. 但考虑到字符只有26个小写英文字母, 使用一个长度为26的数组来保存对应位置的英文字母的数量. 再遍历要比map速度快.
+
+### 代码
+
+```go
+func customSortString(order string, s string) string {
+    a := 'a'
+    result := ""
+    numbers := make([]int, 26)
+    for _, character := range s{
+        numbers[character-a]++
+    }
+    for _,c := range order{
+        temp := numbers[c-a]
+        for i:=0;i<temp;i++{
+            numbers[c-a]--
+            result += string(c)
+        }
+    }
+    for key,c := range numbers{
+        if c!=0{
+            for i:=0;i<c;i++{
+                result += string(rune(int(a)+key))
+            }
+        }
+    }
+    return result
+}
+
+```
+
+### 总结
+
+注意题中条件, 遍历的类型有限的情况下直接使用数组保存, 遍历起来速度要快得多.