Create 6124-first-letter-to-appear-twice.rs

Author: memorycancel

6124-first-letter-to-appear-twice.rs

@@ -0,0 +1,18 @@
+pub fn repeated_character(s: String) -> char {
+    use std::collections::HashMap;
+    let mut mp = HashMap::new();
+    let mut ret = '!';
+    for c in s.chars().collect::<Vec<char>>() {
+        let count = mp.entry(c).or_insert(0);
+        *count += 1;
+        if *count == 2 {
+            ret = c;
+            break;
+        }
+    }
+    ret
+}
+
+fn main() {
+    println!("{:?}", repeated_character("abccbaacz".to_string()));
+}