Create 0387-first-unique-character-in-a-string.java

Author: Tetsuya3850

java/0387-first-unique-character-in-a-string.java

@@ -0,0 +1,14 @@
+class Solution {
+    public int firstUniqChar(String s) {
+        Map<Character, Integer> count = new HashMap<>();
+        for (Character ch : s.toCharArray()) {
+            count.put(ch, count.getOrDefault(ch, 0) + 1);
+        }
+        for (int i = 0; i < s.length(); i++) {
+            if (count.get(s.charAt(i)) == 1) {
+                return i;
+            }
+        }
+        return -1;
+    }
+}