feat: add solutions to lc problem: No.0821

No.0821.Shortest Distance to a Character

Author: YangFong

solution/0800-0899/0821.Shortest Distance to a Character/README.md

@@ -84,6 +84,57 @@ function shortestToChar(s: string, c: string): number[] {
 }
 ```
 
+```ts
+function shortestToChar(s: string, c: string): number[] {
+    const n = s.length;
+    const idxs = [];
+    for (let i = 0; i < n; i++) {
+        if (s[i] === c) {
+            idxs.push(i);
+        }
+    }
+    idxs.push(Infinity);
+
+    const res = new Array(n);
+    let i = 0;
+    for (let j = 0; j < n; j++) {
+        if (Math.abs(idxs[i] - j) > Math.abs(idxs[i + 1] - j)) {
+            i++;
+        }
+        res[j] = Math.abs(idxs[i] - j);
+    }
+    return res;
+}
+```
+
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn shortest_to_char(s: String, c: char) -> Vec<i32> {
+        let c = c as u8;
+        let s = s.as_bytes();
+        let n = s.len();
+        let mut res = vec![i32::MAX; n];
+        let mut pre = i32::MAX;
+        for i in 0..n {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = i32::abs(i as i32 - pre);
+        }
+        pre = i32::MAX;
+        for i in (0..n).rev() {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = res[i].min(i32::abs(i as i32 - pre));
+        }
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0800-0899/0821.Shortest Distance to a Character/README_EN.md

@@ -73,6 +73,57 @@ function shortestToChar(s: string, c: string): number[] {
 }
 ```
 
+```ts
+function shortestToChar(s: string, c: string): number[] {
+    const n = s.length;
+    const idxs = [];
+    for (let i = 0; i < n; i++) {
+        if (s[i] === c) {
+            idxs.push(i);
+        }
+    }
+    idxs.push(Infinity);
+
+    const res = new Array(n);
+    let i = 0;
+    for (let j = 0; j < n; j++) {
+        if (Math.abs(idxs[i] - j) > Math.abs(idxs[i + 1] - j)) {
+            i++;
+        }
+        res[j] = Math.abs(idxs[i] - j);
+    }
+    return res;
+}
+```
+
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn shortest_to_char(s: String, c: char) -> Vec<i32> {
+        let c = c as u8;
+        let s = s.as_bytes();
+        let n = s.len();
+        let mut res = vec![i32::MAX; n];
+        let mut pre = i32::MAX;
+        for i in 0..n {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = i32::abs(i as i32 - pre);
+        }
+        pre = i32::MAX;
+        for i in (0..n).rev() {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = res[i].min(i32::abs(i as i32 - pre));
+        }
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0800-0899/0821.Shortest Distance to a Character/Solution.rs

@@ -0,0 +1,23 @@
+impl Solution {
+    pub fn shortest_to_char(s: String, c: char) -> Vec<i32> {
+        let c = c as u8;
+        let s = s.as_bytes();
+        let n = s.len();
+        let mut res = vec![i32::MAX; n];
+        let mut pre = i32::MAX;
+        for i in 0..n {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = i32::abs(i as i32 - pre);
+        }
+        pre = i32::MAX;
+        for i in (0..n).rev() {
+            if s[i] == c {
+                pre = i as i32;
+            }
+            res[i] = res[i].min(i32::abs(i as i32 - pre));
+        }
+        res
+    }
+}