feat: add rust solution to lc problem: No.1647 (#1610)

Author: xzhseh

solution/1600-1699/1647.Minimum Deletions to Make Character Frequencies Unique/README.md

@@ -192,6 +192,35 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_deletions(s: String) -> i32 {
+        let mut cnt = vec![0; 26];
+        let mut ans = 0;
+
+        for c in s.chars() {
+            cnt[(c as u8 - 'a' as u8) as usize] += 1;
+        }
+
+        cnt.sort_by(|&lhs, &rhs| {
+            rhs.cmp(&lhs)
+        });
+
+        for i in 1..26 {
+            while cnt[i] >= cnt[i - 1] && cnt[i] > 0 {
+                cnt[i] -= 1;
+                ans += 1;
+            }
+        }
+
+        ans
+    }
+}
+```
+
 ### **Go**
 
 ```go

solution/1600-1699/1647.Minimum Deletions to Make Character Frequencies Unique/README_EN.md

@@ -170,6 +170,35 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_deletions(s: String) -> i32 {
+        let mut cnt = vec![0; 26];
+        let mut ans = 0;
+
+        for c in s.chars() {
+            cnt[(c as u8 - 'a' as u8) as usize] += 1;
+        }
+
+        cnt.sort_by(|&lhs, &rhs| {
+            rhs.cmp(&lhs)
+        });
+
+        for i in 1..26 {
+            while cnt[i] >= cnt[i - 1] && cnt[i] > 0 {
+                cnt[i] -= 1;
+                ans += 1;
+            }
+        }
+
+        ans
+    }
+}
+```
+
 ### **Go**
 
 ```go

solution/1600-1699/1647.Minimum Deletions to Make Character Frequencies Unique/Solution.rs

@@ -0,0 +1,24 @@
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_deletions(s: String) -> i32 {
+        let mut cnt = vec![0; 26];
+        let mut ans = 0;
+
+        for c in s.chars() {
+            cnt[(c as u8 - 'a' as u8) as usize] += 1;
+        }
+
+        cnt.sort_by(|&lhs, &rhs| {
+            rhs.cmp(&lhs)
+        });
+
+        for i in 1..26 {
+            while cnt[i] >= cnt[i - 1] && cnt[i] > 0 {
+                cnt[i] -= 1;
+                ans += 1;
+            }
+        }
+
+        ans
+    }
+}