leetcode update

content/posts/leetcode.md

@@ -16908,3 +16908,90 @@ public:
     }
 };
 ```
+
+## day239 2024-11-02
+
+### 2490. Circular Sentence
+
+A sentence is a list of words that are separated by a single space with no leading or trailing spaces.
+
+For example, "Hello World", "HELLO", "hello world hello world" are all sentences.
+Words consist of only uppercase and lowercase English letters. Uppercase and lowercase English letters are considered different.
+
+A sentence is circular if:
+
+The last character of a word is equal to the first character of the next word.
+The last character of the last word is equal to the first character of the first word.
+For example, "leetcode exercises sound delightful", "eetcode", "leetcode eats soul" are all circular sentences. However, "Leetcode is cool", "happy Leetcode", "Leetcode" and "I like Leetcode" are not circular sentences.
+
+Given a string sentence, return true if it is circular. Otherwise, return false.
+
+![1102pGUOgMp8TmkY](https://testingcf.jsdelivr.net/gh/game-loader/picbase@master/uPic/1102pGUOgMp8TmkY.png)
+
+### 题解
+
+本题是一道简单题，先判断句子的首尾字符是否相同，不同直接返回false。再遍历句子，每当下一个字符为空格时，考虑到题目中明确说明单词和单词之间只有一个空格分隔，则判断当前字符和下下个字符是否相等，不相等直接返回false。遍历完成则返回true。
+
+### 代码
+
+```cpp
+class Solution {
+public:
+    bool isCircularSentence(string sentence) {
+        if(sentence[0] != sentence[sentence.size()-1]){
+            return false;
+        }
+        for (int i=0;i<sentence.size()-1;i++){
+            if (sentence[i+1] == ' ' && sentence[i+2] != sentence[i]){
+                return false;
+            }
+        }
+        return true;
+    }
+};
+```
+
+## day240 2024-11-03
+
+### 796. Rotate String
+
+Given two strings s and goal, return true if and only if s can become goal after some number of shifts on s.
+
+A shift on s consists of moving the leftmost character of s to the rightmost position.
+
+For example, if s = "abcde", then it will be "bcdea" after one shift.
+
+![1103j7mfXJbRERz7](https://testingcf.jsdelivr.net/gh/game-loader/picbase@master/uPic/1103j7mfXJbRERz7.png)
+
+### 题解
+
+本题是一道简单题，一个比较容易想到的思路是对于s，选定开头字母如字母a作为整个循环字符串的起始，随后遍历goal字符串，遇到字符a就将其当作s的开头字符a，向后遍历goal字符串并与s比对，成功则为true，失败则继续遍历goal寻找下一个a，直到遍历完整个goal为止。
+
+### 代码
+
+```cpp
+class Solution {
+public:
+    bool rotateString(string s, string goal) {
+        if (s.size() != goal.size()){
+            return false;
+        }
+        char label = s[0];
+        for (int i=0;i<goal.size();i++){
+            if (goal[i] == label){
+                bool success = true;
+                for (int j=0;j<s.size();j++){
+                    if(s[j] != goal[(i+j)%s.size()]){
+                        success = false;
+                        break;
+                    }
+                }
+                if (success){
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+};
+```