一刷316

Author: diguage

README.adoc

@@ -7592,14 +7592,14 @@ TIP: **公众号的微信号是: `jikerizhi`**。__因为众所周知的原因
 //|{doc_base_url}/1080-insufficient-nodes-in-root-to-leaf-paths.adoc[题解]
 //|Medium
 //|
-//
-//|{counter:codes}
-//|{leetcode_base_url}/smallest-subsequence-of-distinct-characters/[1081. Smallest Subsequence of Distinct Characters^]
-//|{source_base_url}/_1081_SmallestSubsequenceOfDistinctCharacters.java[Java]
-//|{doc_base_url}/1081-smallest-subsequence-of-distinct-characters.adoc[题解]
-//|Medium
-//|
-//
+
+|{counter:codes}
+|{leetcode_base_url}/smallest-subsequence-of-distinct-characters/[1081. Smallest Subsequence of Distinct Characters^]
+|{source_base_url}/_1081_SmallestSubsequenceOfDistinctCharacters.java[Java]
+|{doc_base_url}/1081-smallest-subsequence-of-distinct-characters.adoc[题解]
+|Medium
+|
+
 //|{counter:codes}
 //|{leetcode_base_url}/sales-analysis-i/[1082. Sales Analysis I^]
 //|{source_base_url}/_1082_SalesAnalysisI.java[Java]

docs/0316-remove-duplicate-letters.adoc

@@ -26,7 +26,9 @@ https://leetcode.cn/problems/remove-duplicate-letters/[LeetCode - 316. 去除重
 
 == 思路分析
 
-先遍历字符串，统计每个字符的出现次数。
+先遍历字符串，统计每个字符的出现次数。然后依次添加，遇到当前字符小于上次字符时，在上次字符在剩余字符串中还有时，则将上述字符“弹出”。循环弹出，直到循环结束。添加当前字符，记录添加状态。
+
+注意，在遍历字符时，向前走一步，则当前字符的次数就要减一。
 
 [[src-0316]]
 [tabs]

docs/1081-smallest-subsequence-of-distinct-characters.adoc

@@ -1,65 +1,59 @@
 [#1081-smallest-subsequence-of-distinct-characters]
-= 1081. Smallest Subsequence of Distinct Characters
+= 1081. 不同字符的最小子序列
 
-{leetcode}/problems/smallest-subsequence-of-distinct-characters/[LeetCode - Smallest Subsequence of Distinct Characters^]
+https://leetcode.cn/problems/smallest-subsequence-of-distinct-characters/[LeetCode - 1081. 不同字符的最小子序列 ^]
 
-Return the lexicographically smallest subsequence of `text` that contains all the distinct characters of `text` exactly once.
+返回 `s` 字典序最小的子序列，该子序列包含 `s` 的所有不同字符，且只包含一次。
 
- 
+*示例 1：*
 
-*Example 1:*
+....
+输入：s = "bcabc"
+输出："abc"
+....
 
-[subs="verbatim,quotes,macros"]
-----
-*Input:* "cdadabcc"
-*Output:* "adbc"
-----
+*示例 2：*
 
+....
+输入：s = "cbacdcbc"
+输出："acdb"
+....
 
-*Example 2:*
+*提示：*
 
-[subs="verbatim,quotes,macros"]
-----
-*Input:* "abcd"
-*Output:* "abcd"
-----
+* `+1 <= s.length <= 1000+`
+* `s` 由小写英文字母组成
 
+**注意：**该题与 xref:0316-remove-duplicate-letters.adoc[316. Remove Duplicate Letters] 相同
 
-*Example 3:*
 
-[subs="verbatim,quotes,macros"]
-----
-*Input:* "ecbacba"
-*Output:* "eacb"
-----
+== 思路分析
 
+该题与 xref:0316-remove-duplicate-letters.adoc[316. Remove Duplicate Letters] 相同，不再赘述。
 
-*Example 4:*
-
-[subs="verbatim,quotes,macros"]
+[[src-1081]]
+[tabs]
+====
+一刷::
++
+--
+[{java_src_attr}]
 ----
-*Input:* "leetcode"
-*Output:* "letcod"
+include::{sourcedir}/_1081_SmallestSubsequenceOfDistinctCharacters.java[tag=answer]
 ----
+--
 
- 
-
-*Note:*
+// 二刷::
+// +
+// --
+// [{java_src_attr}]
+// ----
+// include::{sourcedir}/_1081_SmallestSubsequenceOfDistinctCharacters_2.java[tag=answer]
+// ----
+// --
+====
 
 
-. `1 <= text.length <= 1000`
-. `text` consists of lowercase English letters.
+== 参考资料
 
 
- 
-
-
-
-
-
-[[src-1081]]
-[{java_src_attr}]
-----
-include::{sourcedir}/_1081_SmallestSubsequenceOfDistinctCharacters.java[tag=answer]
-----
-

docs/index.adoc

@@ -2244,7 +2244,7 @@ include::1041-robot-bounded-in-circle.adoc[leveloffset=+1]
 
 // include::1080-insufficient-nodes-in-root-to-leaf-paths.adoc[leveloffset=+1]
 
-// include::1081-smallest-subsequence-of-distinct-characters.adoc[leveloffset=+1]
+include::1081-smallest-subsequence-of-distinct-characters.adoc[leveloffset=+1]
 
 // include::1082-sales-analysis-i.adoc[leveloffset=+1]
 

logbook/202503.adoc

@@ -65,7 +65,7 @@ endif::[]
 
 |{counter:codes2503}
 |{leetcode_base_url}/remove-duplicate-letters/[316. 去除重复字母^]
-|{doc_base_url}/316. 去除重复字母[题解]
+|{doc_base_url}/0316-remove-duplicate-letters.adoc[题解]
 |❌ 完全想不到单调栈！
 
 |{counter:codes2503}
@@ -428,11 +428,15 @@ endif::[]
 |{doc_base_url}/0128-longest-consecutive-sequence.adoc[题解]
 |⭕️ 最初思路是排序。看答案，可以构建集合，然后“起点”（没有前一个数字）数字开始统计。
 
-|{counter:codes}
+|{counter:codes2503}
 |{leetcode_base_url}/design-linked-list/[707. 设计链表^]
 |{doc_base_url}/0707-design-linked-list.adoc[题解]
 |✅
 
+|{counter:codes2503}
+|{leetcode_base_url}/smallest-subsequence-of-distinct-characters/[1081. 不同字符的最小子序列^]
+|{doc_base_url}/1081-smallest-subsequence-of-distinct-characters.adoc[题解]
+|❌ 单调栈，与 {doc_base_url}/0316-remove-duplicate-letters.adoc[316. Remove Duplicate Letters] 相同。知道用单调栈，但还是没写出来。
 
 |===
 

src/main/java/com/diguage/algo/leetcode/_1081_SmallestSubsequenceOfDistinctCharacters.java

@@ -0,0 +1,45 @@
+package com.diguage.algo.leetcode;
+
+public class _1081_SmallestSubsequenceOfDistinctCharacters {
+  // tag::answer[]
+
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2025-04-22 16:54:12
+   */
+  public String smallestSubsequence(String s) {
+    char[] chars = s.toCharArray();
+    int[] counts = new int[26];
+    for (char c : chars) {
+      counts[c - 'a']++;
+    }
+    boolean[] used = new boolean[26];
+    StringBuilder sb = new StringBuilder(26);
+    for (char c : chars) {
+      int idx = c - 'a';
+      counts[idx]--;
+      if (used[idx]) {
+        continue;
+      }
+      while (!sb.isEmpty()
+        && sb.charAt(sb.length() - 1) > c) {
+        int lastIndex = sb.length() - 1;
+        int tid = sb.charAt(lastIndex) - 'a';
+        if (counts[tid] == 0) {
+          break;
+        } else {
+          sb.deleteCharAt(lastIndex);
+          used[tid] = false;
+        }
+      }
+      sb.append(c);
+      used[idx] = true;
+    }
+    return sb.toString();
+  }
+  // end::answer[]
+  public static void main(String[] args) {
+    new _1081_SmallestSubsequenceOfDistinctCharacters()
+      .smallestSubsequence("bcabc");
+  }
+}