src/bin/greatest-english-letter-in-upper-and-lower-case.rs

Author: bestgopher

src/bin/greatest-english-letter-in-upper-and-lower-case.rs

@@ -0,0 +1,39 @@
+#![allow(dead_code, unused, unused_variables, non_snake_case)]
+
+use std::cmp::max;
+
+fn main() {}
+
+struct Solution;
+
+impl Solution {
+    pub fn greatest_letter(s: String) -> String {
+        let mut r = "".to_owned();
+        let mut v = vec![0u8; 26]; // 0代表没有，1代表小写，2代表大写
+
+        for i in 0..s.as_bytes().len() {
+            let m = s.as_bytes()[i];
+            match m {
+                b'A'..=b'Z' => {
+                    if v[(m - b'A') as usize] == 1 {
+                        r = r.max(s.as_str()[i..i + 1].to_string());
+                        v[(m - b'A') as usize] = 3;
+                    } else {
+                        v[(m - b'A') as usize] = 2;
+                    }
+                }
+                b'a'..=b'z' => {
+                    if v[(m - b'a') as usize] == 2 {
+                        r = r.max(s.as_str()[i..i + 1].to_string().to_uppercase());
+                        v[(m - b'a') as usize] = 3;
+                    } else {
+                        v[(m - b'a') as usize] = 1;
+                    }
+                }
+                _ => unreachable!(),
+            }
+        }
+
+        r
+    }
+}