solve problem First Unique Character In A String

Author: P-ppc

README.md

@@ -140,6 +140,7 @@ All solutions will be accepted!
 |205|[Isomorphic Strings](https://leetcode-cn.com/problems/isomorphic-strings/description/)|[java/py/js](./algorithms/IsomorphicStrings)|Easy|
 |125|[Valid Palindrome](https://leetcode-cn.com/problems/valid-palindrome/description/)|[java/py/js](./algorithms/ValidPalindrome)|Easy|
 |141|[Linked List Cycle](https://leetcode-cn.com/problems/linked-list-cycle/description/)|[java/py/js](./algorithms/LinkedListCycle)|Easy|
+|387|[First Unique Character In A String](https://leetcode-cn.com/problems/first-unique-character-in-a-string/description/)|[java/py/js](./algorithms/FirstUniqueCharacterInAString)|Easy|
 
 # Database
 |#|Title|Solution|Difficulty|

algorithms/FirstUniqueCharacterInAString/README.md

@@ -0,0 +1,2 @@
+# First Unique Character In A String
+This problme is easy to solve by hashmap

algorithms/FirstUniqueCharacterInAString/Solution.java

@@ -0,0 +1,21 @@
+class Solution {
+    public int firstUniqChar(String s) {
+        Map<Character, Integer> characterMap = new HashMap<Character, Integer>();
+        
+        for (int i = 0; i < s.length(); i++) {
+            char c = s.charAt(i);
+            if (characterMap.get(c) == null) {
+                characterMap.put(c, 1);
+            } else {
+                characterMap.put(c, characterMap.get(c) + 1);
+            }
+        }
+        
+        for (int i = 0; i < s.length(); i++) {
+            if (characterMap.get(s.charAt(i)) == 1) {
+                return i;
+            }
+        }
+        return -1;
+    }
+}

algorithms/FirstUniqueCharacterInAString/solution.js

@@ -0,0 +1,24 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var firstUniqChar = function(s) {
+    let characterMap = {}
+    
+    for (let i = 0; i < s.length; i++) {
+        let c = s[i]
+        if (characterMap[c] === undefined) {
+            characterMap[c] = 1
+        } else {
+            characterMap[c]++
+        }
+    }
+    
+    for (let i = 0; i < s.length; i++) {
+        if (characterMap[s[i]] === 1) {
+            return i
+        }
+    }
+    
+    return -1
+};

algorithms/FirstUniqueCharacterInAString/solution.py

@@ -0,0 +1,19 @@
+class Solution(object):
+    def firstUniqChar(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        character_map = {}
+        
+        for c in s:
+            if character_map.get(c) == None:
+                character_map[c] = 1
+            else:
+                character_map[c] += 1
+        
+        for i in range(len(s)):
+            if character_map[s[i]] == 1:
+                return i
+        
+        return -1