feat: add python and java solutions to leetcode problem: No.0387

Author: yanglbme

solution/0300-0399/0387.First Unique Character in a String/README.md

@@ -25,22 +25,48 @@ s = "loveleetcode",
 
 <!-- 这里可写通用的实现逻辑 -->
 
+遍历字符串，用一个 map 或者字典存放字符串中每个字符出现的次数。然后再次遍历字符串，取出对应字符出现的次数，若次数为 1，直接返回当前字符串的下标。遍历结束，返回 -1。
+
 <!-- tabs:start -->
 
 ### **Python3**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
-
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        chars = {}
+        for ch in s:
+            ch = ord(ch)
+            chars[ch] = chars.get(ch, 0) + 1
+        for i, ch in enumerate(s):
+            ch = ord(ch)
+            if chars[ch] == 1:
+                return i
+        return -1
 ```
 
 ### **Java**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
-
+class Solution {
+    public int firstUniqChar(String s) {
+        Map<Character, Integer> chars = new HashMap<>(26);
+        int n = s.length();
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            chars.put(ch, chars.getOrDefault(ch, 0) + 1);
+        }
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            if (chars.get(ch) == 1) return i;
+        }
+        return -1;
+    }
+}
 ```
 
 ### **...**

solution/0300-0399/0387.First Unique Character in a String/README_EN.md

@@ -41,13 +41,37 @@ return 2.
 ### **Python3**
 
 ```python
-
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        chars = {}
+        for ch in s:
+            ch = ord(ch)
+            chars[ch] = chars.get(ch, 0) + 1
+        for i, ch in enumerate(s):
+            ch = ord(ch)
+            if chars[ch] == 1:
+                return i
+        return -1
 ```
 
 ### **Java**
 
 ```java
-
+class Solution {
+    public int firstUniqChar(String s) {
+        Map<Character, Integer> chars = new HashMap<>(26);
+        int n = s.length();
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            chars.put(ch, chars.getOrDefault(ch, 0) + 1);
+        }
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            if (chars.get(ch) == 1) return i;
+        }
+        return -1;
+    }
+}
 ```
 
 ### **...**

solution/0300-0399/0387.First Unique Character in a String/Solution.java

@@ -0,0 +1,15 @@
+class Solution {
+    public int firstUniqChar(String s) {
+        Map<Character, Integer> chars = new HashMap<>(26);
+        int n = s.length();
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            chars.put(ch, chars.getOrDefault(ch, 0) + 1);
+        }
+        for (int i = 0; i < n; ++i) {
+            char ch = s.charAt(i);
+            if (chars.get(ch) == 1) return i;
+        }
+        return -1;
+    }
+}

solution/0300-0399/0387.First Unique Character in a String/Solution.py

@@ -0,0 +1,11 @@
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        chars = {}
+        for ch in s:
+            ch = ord(ch)
+            chars[ch] = chars.get(ch, 0) + 1
+        for i, ch in enumerate(s):
+            ch = ord(ch)
+            if chars[ch] == 1:
+                return i
+        return -1