二刷387

Author: diguage

docs/0387-first-unique-character-in-a-string.adoc

@@ -22,11 +22,38 @@ return 2.
 
 *Note:* You may assume the string contain only lowercase letters.
 
+== 思路分析
 
+通过解法是再次遍历字符串，思考如何遍历字母表来获取第一个唯一字符的位置。
 
 [[src-0387]]
+[tabs]
+====
+一刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0387_FirstUniqueCharacterInAString.java[tag=answer]
 ----
+--
+
+二刷::
++
+--
+[{java_src_attr}]
+----
+include::{sourcedir}/_0387_FirstUniqueCharacterInAString_2.java[tag=answer]
+----
+--
+====
+
+== 参考资料
+
+. https://leetcode.cn/problems/first-unique-character-in-a-string/solutions/2361521/387-zi-fu-chuan-zhong-de-di-yi-ge-wei-yi-c5md/?envType=study-plan-v2&envId=selected-coding-interview[387. 字符串中的第一个唯一字符 - 哈希表，清晰图解^]
+. https://leetcode.cn/problems/first-unique-character-in-a-string/solutions/531740/zi-fu-chuan-zhong-de-di-yi-ge-wei-yi-zi-x9rok/?envType=study-plan-v2&envId=selected-coding-interview[387. 字符串中的第一个唯一字符 - 官方题解^]
+
+
+
+
 

logbook/202406.adoc

@@ -545,6 +545,11 @@
 |{doc_base_url}/0155-min-stack.adoc[题解]
 |对，这也是单调栈。
 
+|{counter:codes}
+|{leetcode_base_url}/first-unique-character-in-a-string/[387. First Unique Character in a String^]
+|{doc_base_url}/0387-first-unique-character-in-a-string.adoc[题解]
+|哈希+字符串
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

src/main/java/com/diguage/algo/leetcode/_0387_FirstUniqueCharacterInAString.java

@@ -35,6 +35,9 @@ public class _0387_FirstUniqueCharacterInAString {
      * Memory Usage: 37.4 MB, less than 100.00% of Java online submissions for First Unique Character in a String.
      *
      * Copy from: https://leetcode.com/problems/first-unique-character-in-a-string/solution/[First Unique Character in a String solution - LeetCode]
+     *
+     * @author D瓜哥 · https://www.diguage.com
+     * @since 2020-01-11 10:48
      */
     public int firstUniqChar(String s) {
         if (Objects.isNull(s) || s.length() == 0) {

src/main/java/com/diguage/algo/leetcode/_0387_FirstUniqueCharacterInAString_2.java

@@ -0,0 +1,27 @@
+package com.diguage.algo.leetcode;
+
+import java.util.Arrays;
+
+public class _0387_FirstUniqueCharacterInAString_2 {
+  // tag::answer[]
+
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2020-01-11 10:48
+   */
+  public int firstUniqChar(String s) {
+    int[] cnt = new int[26];
+    for (int i = 0; i < s.length(); i++) {
+      int idx = s.charAt(i) - 'a';
+      cnt[idx]++;
+    }
+    for (int i = 0; i < s.length(); i++) {
+      int idx = s.charAt(i) - 'a';
+      if (cnt[idx] == 1) {
+        return i;
+      }
+    }
+    return -1;
+  }
+  // end::answer[]
+}