feat: add rust solution to lc problems: No.2278,2279

- No.2278.Percentage of Letter in String
- No.2279.Maximum Bags With Full Capacity of Rocks

Author: YangFong

solution/2200-2299/2278.Percentage of Letter in String/README.md

@@ -112,6 +112,22 @@ function percentageLetter(s: string, letter: string): number {
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn percentage_letter(s: String, letter: char) -> i32 {
+        let mut count = 0;
+        for c in s.chars() {
+            if c == letter {
+                count += 1;
+            }
+        }
+        (count * 100 / s.len()) as i32
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2200-2299/2278.Percentage of Letter in String/README_EN.md

@@ -102,6 +102,22 @@ function percentageLetter(s: string, letter: string): number {
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn percentage_letter(s: String, letter: char) -> i32 {
+        let mut count = 0;
+        for c in s.chars() {
+            if c == letter {
+                count += 1;
+            }
+        }
+        (count * 100 / s.len()) as i32
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2200-2299/2278.Percentage of Letter in String/Solution.rs

@@ -0,0 +1,11 @@
+impl Solution {
+    pub fn percentage_letter(s: String, letter: char) -> i32 {
+        let mut count = 0;
+        for c in s.chars() {
+            if c == letter {
+                count += 1;
+            }
+        }
+        (count * 100 / s.len()) as i32
+    }
+}

solution/2200-2299/2279.Maximum Bags With Full Capacity of Rocks/README.md

@@ -164,6 +164,28 @@ function maximumBags(capacity: number[], rocks: number[], additionalRocks: numbe
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn maximum_bags(capacity: Vec<i32>, rocks: Vec<i32>, mut additional_rocks: i32) -> i32 {
+        let n = capacity.len();
+        let mut diffs = vec![0; n];
+        for i in 0..n {
+            diffs[i] = capacity[i] - rocks[i];
+        }
+        diffs.sort();
+        for i in 0..n {
+            if diffs[i] > additional_rocks {
+                return i as i32;
+            }
+            additional_rocks -= diffs[i];
+        }
+        n as i32
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2200-2299/2279.Maximum Bags With Full Capacity of Rocks/README_EN.md

@@ -153,6 +153,28 @@ function maximumBags(capacity: number[], rocks: number[], additionalRocks: numbe
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn maximum_bags(capacity: Vec<i32>, rocks: Vec<i32>, mut additional_rocks: i32) -> i32 {
+        let n = capacity.len();
+        let mut diffs = vec![0; n];
+        for i in 0..n {
+            diffs[i] = capacity[i] - rocks[i];
+        }
+        diffs.sort();
+        for i in 0..n {
+            if diffs[i] > additional_rocks {
+                return i as i32;
+            }
+            additional_rocks -= diffs[i];
+        }
+        n as i32
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2200-2299/2279.Maximum Bags With Full Capacity of Rocks/Solution.rs

@@ -0,0 +1,17 @@
+impl Solution {
+    pub fn maximum_bags(capacity: Vec<i32>, rocks: Vec<i32>, mut additional_rocks: i32) -> i32 {
+        let n = capacity.len();
+        let mut diffs = vec![0; n];
+        for i in 0..n {
+            diffs[i] = capacity[i] - rocks[i];
+        }
+        diffs.sort();
+        for i in 0..n {
+            if diffs[i] > additional_rocks {
+                return i as i32;
+            }
+            additional_rocks -= diffs[i];
+        }
+        n as i32
+    }
+}