一刷724

Author: diguage

README.adoc

@@ -5093,14 +5093,14 @@ TIP: **公众号的微信号是: `jikerizhi`**。__因为众所周知的原因
 //|{doc_base_url}/0723-candy-crush.adoc[题解]
 //|Medium
 //|
-//
-//|{counter:codes}
-//|{leetcode_base_url}/find-pivot-index/[724. Find Pivot Index^]
-//|{source_base_url}/_0724_FindPivotIndex.java[Java]
-//|{doc_base_url}/0724-find-pivot-index.adoc[题解]
-//|Easy
-//|
-//
+
+|{counter:codes}
+|{leetcode_base_url}/find-pivot-index/[724. Find Pivot Index^]
+|{source_base_url}/_0724_FindPivotIndex.java[Java]
+|{doc_base_url}/0724-find-pivot-index.adoc[题解]
+|Easy
+|
+
 //|{counter:codes}
 //|{leetcode_base_url}/split-linked-list-in-parts/[725. Split Linked List in Parts^]
 //|{source_base_url}/_0725_SplitLinkedListInParts.java[Java]

docs/0000-03-prefix-sum.adoc

@@ -8,6 +8,8 @@
 . xref:0303-range-sum-query-immutable.adoc[303. Range Sum Query - Immutable]
 . xref:0304-range-sum-query-2d-immutable.adoc[304. Range Sum Query 2D - Immutable]
 . xref:0437-path-sum-iii.adoc[437. Path Sum III]
+. xref:0238-product-of-array-except-self.adoc[238. Product of Array Except Self]
+. xref:0724-find-pivot-index.adoc[724. Find Pivot Index]
 
 == 参考资料
 

docs/0238-product-of-array-except-self.adoc

@@ -45,6 +45,8 @@ include::{sourcedir}/_0238_ProductOfArrayExceptSelf_2.java[tag=answer]
 --
 ====
 
+该题的思路也适用于 xref:0724-find-pivot-index.adoc[724. Find Pivot Index]。
+
 == 参考资料
 
 . https://leetcode.cn/problems/product-of-array-except-self/solutions/11472/product-of-array-except-self-shang-san-jiao-xia-sa/?envType=study-plan-v2&envId=selected-coding-interview[238. 除自身以外数组的乘积 - 清晰图解^]

docs/0724-find-pivot-index.adoc

@@ -44,12 +44,38 @@ There is no index that satisfies the conditions in the problem statement.
 
 
 
+== 思路分析
 
+这道题的技巧和 xref:0238-product-of-array-except-self.adoc[238. Product of Array Except Self] 类似。
 
+image::images/0724-01.gif[{image_attr}]
+
+看答案，也可以直接求和，然后在依次相加减得到两边的和。
 
 [[src-0724]]
+[tabs]
+====
+一刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0724_FindPivotIndex.java[tag=answer]
 ----
+--
+
+// 二刷::
+// +
+// --
+// [{java_src_attr}]
+// ----
+// include::{sourcedir}/_0724_FindPivotIndex_2.java[tag=answer]
+// ----
+// --
+====
+
+== 参考资料
+
+. https://leetcode.cn/problems/find-pivot-index/solutions/1645928/by-jyd-9265/?envType=study-plan-v2&envId=selected-coding-interview[724. 寻找数组的中心下标 - 前缀和，清晰图解^]
+
 

docs/images/0724-01.gif

@@ -1522,7 +1522,7 @@ include::0714-best-time-to-buy-and-sell-stock-with-transaction-fee.adoc[leveloff
 
 // include::0723-candy-crush.adoc[leveloffset=+1]
 
-// include::0724-find-pivot-index.adoc[leveloffset=+1]
+include::0724-find-pivot-index.adoc[leveloffset=+1]
 
 // include::0725-split-linked-list-in-parts.adoc[leveloffset=+1]
 

docs/index.adoc

@@ -533,7 +533,7 @@
 |{counter:codes}
 |{leetcode_base_url}/product-of-array-except-self/[238. Product of Array Except Self^]
 |{doc_base_url}/0238-product-of-array-except-self.adoc[题解]
-|从后及从前，在一个数组上分两次进行计算
+|✅ 前缀和，从后及从前，在一个数组上分两次进行计算
 
 |{counter:codes}
 |{leetcode_base_url}/partition-list/[86. Partition List^]
@@ -691,6 +691,13 @@
 |{doc_base_url}/0006-zigzag-conversion.adoc[题解]
 |❌ 注意审题，看题！
 
+
+|{counter:codes}
+|{leetcode_base_url}/find-pivot-index/[724. Find Pivot Index^]
+|{doc_base_url}/0724-find-pivot-index.adoc[题解]
+|✅ 前缀和
+
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

logbook/202406.adoc

@@ -0,0 +1,30 @@
+package com.diguage.algo.leetcode;
+
+public class _0724_FindPivotIndex {
+  // tag::answer[]
+
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-18 21:45:49
+   */
+  public int pivotIndex(int[] nums) {
+    int length = nums.length;
+    int[] dp = new int[length + 2];
+    for (int i = length; i > 0; i--) {
+      dp[i] = nums[i - 1] + dp[i + 1];
+    }
+    for (int i = 1; i <= length; i++) {
+      if (dp[i - 1] == dp[i + 1]) {
+        return i - 1;
+      }
+      dp[i] = nums[i - 1] + dp[i - 1];
+    }
+    return -1;
+  }
+
+  // end::answer[]
+  public static void main(String[] args) {
+    new _0724_FindPivotIndex()
+      .pivotIndex(new int[]{-1, -1, 0, 0, -1, -1});
+  }
+}