feat: add solutions to lc problem: No.0784

No.0784.Letter Case Permutation

Author: YangFong

solution/0700-0799/0784.Letter Case Permutation/README.md

@@ -151,6 +151,54 @@ func letterCasePermutation(s string) []string {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function letterCasePermutation(s: string): string[] {
+    const n = s.length;
+    const cs = [...s];
+    const res = [];
+    const dfs = (i: number) => {
+        if (i === n) {
+            res.push(cs.join(''));
+            return;
+        }
+        dfs(i + 1);
+        if (cs[i] >= 'A') {
+            cs[i] = String.fromCharCode(cs[i].charCodeAt(0) ^ 32);
+            dfs(i + 1);
+        }
+    };
+    dfs(0);
+    return res;
+}
+```
+
+### **Rust**
+
+```rust
+impl Solution {
+    fn dfs(i: usize, cs: &mut Vec<char>, res: &mut Vec<String>) {
+        if i == cs.len() {
+            res.push(cs.iter().collect());
+            return;
+        }
+        Self::dfs(i + 1, cs, res);
+        if cs[i] >= 'A' {
+            cs[i] = char::from((cs[i] as u8) ^ 32);
+            Self::dfs(i + 1, cs, res);
+        }
+    }
+
+    pub fn letter_case_permutation(s: String) -> Vec<String> {
+        let mut res = Vec::new();
+        let mut cs = s.chars().collect::<Vec<char>>();
+        Self::dfs(0, &mut cs, &mut res);
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0700-0799/0784.Letter Case Permutation/README_EN.md

@@ -133,6 +133,54 @@ func letterCasePermutation(s string) []string {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function letterCasePermutation(s: string): string[] {
+    const n = s.length;
+    const cs = [...s];
+    const res = [];
+    const dfs = (i: number) => {
+        if (i === n) {
+            res.push(cs.join(''));
+            return;
+        }
+        dfs(i + 1);
+        if (cs[i] >= 'A') {
+            cs[i] = String.fromCharCode(cs[i].charCodeAt(0) ^ 32);
+            dfs(i + 1);
+        }
+    };
+    dfs(0);
+    return res;
+}
+```
+
+### **Rust**
+
+```rust
+impl Solution {
+    fn dfs(i: usize, cs: &mut Vec<char>, res: &mut Vec<String>) {
+        if i == cs.len() {
+            res.push(cs.iter().collect());
+            return;
+        }
+        Self::dfs(i + 1, cs, res);
+        if cs[i] >= 'A' {
+            cs[i] = char::from((cs[i] as u8) ^ 32);
+            Self::dfs(i + 1, cs, res);
+        }
+    }
+
+    pub fn letter_case_permutation(s: String) -> Vec<String> {
+        let mut res = Vec::new();
+        let mut cs = s.chars().collect::<Vec<char>>();
+        Self::dfs(0, &mut cs, &mut res);
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0700-0799/0784.Letter Case Permutation/Solution.rs

@@ -0,0 +1,20 @@
+impl Solution {
+    fn dfs(i: usize, cs: &mut Vec<char>, res: &mut Vec<String>) {
+        if i == cs.len() {
+            res.push(cs.iter().collect());
+            return;
+        }
+        Self::dfs(i + 1, cs, res);
+        if cs[i] >= 'A' {
+            cs[i] = char::from((cs[i] as u8) ^ 32);
+            Self::dfs(i + 1, cs, res);
+        }
+    }
+
+    pub fn letter_case_permutation(s: String) -> Vec<String> {
+        let mut res = Vec::new();
+        let mut cs = s.chars().collect::<Vec<char>>();
+        Self::dfs(0, &mut cs, &mut res);
+        res
+    }
+}

solution/0700-0799/0784.Letter Case Permutation/Solution.ts

@@ -0,0 +1,18 @@
+function letterCasePermutation(s: string): string[] {
+    const n = s.length;
+    const cs = [...s];
+    const res = [];
+    const dfs = (i: number) => {
+        if (i === n) {
+            res.push(cs.join(''));
+            return;
+        }
+        dfs(i + 1);
+        if (cs[i] >= 'A') {
+            cs[i] = String.fromCharCode(cs[i].charCodeAt(0) ^ 32);
+            dfs(i + 1);
+        }
+    };
+    dfs(0);
+    return res;
+}