二刷240

Author: diguage

docs/0240-search-a-2d-matrix-ii.adoc

@@ -3,10 +3,6 @@
 
 {leetcode}/problems/search-a-2d-matrix-ii/[LeetCode - Search a 2D Matrix II^]
 
-从右上角开始搜索，小则下移，大则左移，这个方案真是精妙！
-
-image:images/0240-1.jpg[]
-
 
 Write an efficient algorithm that searches for a value in an _m_ x _n_ matrix. This matrix has the following properties:
 
@@ -35,10 +31,50 @@ Given target = `5`, return `true`.
 Given target = `20`, return `false`.
 
 
+== 思路分析
+
+不能对真个矩阵进行二分查找！可以对单行做二分查找。
+
+从右上角开始搜索，小则下移，大则左移，这个方案真是精妙！
+
+image::images/0240-01.png[{image_attr}]
+
+image::images/0240-02.png[{image_attr}]
+
+image::images/0240-03.png[{image_attr}]
+
+image::images/0240-04.png[{image_attr}]
+
+image::images/0240-05.png[{image_attr}]
+
+image::images/0240-06.png[{image_attr}]
 
 [[src-0240]]
+[tabs]
+====
+一刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0240_SearchA2DMatrixII.java[tag=answer]
 ----
+--
+
+二刷::
++
+--
+[{java_src_attr}]
+----
+include::{sourcedir}/_0240_SearchA2DMatrixII_2.java[tag=answer]
+----
+--
+====
+
+== 参考资料
+
+. https://leetcode.cn/problems/search-a-2d-matrix-ii/solutions/1062538/sou-suo-er-wei-ju-zhen-ii-by-leetcode-so-9hcx/?envType=study-plan-v2&envId=selected-coding-interview[240. 搜索二维矩阵 II - 官方题解^]
+. https://leetcode.cn/problems/search-a-2d-matrix-ii/solutions/2361487/240-sou-suo-er-wei-ju-zhen-iitan-xin-qin-7mtf/?envType=study-plan-v2&envId=selected-coding-interview[240. 搜索二维矩阵 II - 贪心，清晰图解^]
+
+
 

docs/images/0240-01.png

@@ -585,6 +585,11 @@
 |{doc_base_url}/0050-powx-n.adoc[题解]
 |分治，快速幂，迭代实现还需要再思考理解一下。
 
+|{counter:codes}
+|{leetcode_base_url}/search-a-2d-matrix-ii/[240. Search a 2D Matrix II^]
+|{doc_base_url}/0240-search-a-2d-matrix-ii.adoc[题解]
+|不能对矩阵做二分查找，可以对单行做二分查找。要分析题目，查看如何排除不符合要求的元素。
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

docs/images/0240-02.png

@@ -4,7 +4,7 @@ public class _0050_PowXN_2 {
   // tag::answer[]
   /**
    * @author D瓜哥 · https://www.diguage.com
-   * @since 2020-01-13 21:19
+   * @since 2024-09-15 17:13:46
    */
   public double myPow(double x, long n) {
     if (x == 0) {

docs/images/0240-03.png

@@ -41,6 +41,9 @@ public class _0240_SearchA2DMatrixII {
      * Memory Usage: 50.3 MB, less than 5.66% of Java online submissions for Search a 2D Matrix II.
      *
      * Copy from: https://leetcode.com/problems/search-a-2d-matrix-ii/discuss/66140/My-concise-O(m%2Bn)-Java-solution[(1) My concise O(m+n) Java solution - LeetCode Discuss]
+     *
+     * @author D瓜哥 · https://www.diguage.com
+     * @since 2020-01-23 10:04
      */
     public boolean searchMatrix(int[][] matrix, int target) {
         if (Objects.isNull(matrix) || matrix.length == 0) {

docs/images/0240-04.png

@@ -0,0 +1,25 @@
+package com.diguage.algo.leetcode;
+
+public class _0240_SearchA2DMatrixII_2 {
+  // tag::answer[]
+
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-15 18:14:17
+   */
+  public boolean searchMatrix(int[][] matrix, int target) {
+    int row = 0, column = matrix[0].length - 1;
+    while (row < matrix.length && 0 <= column) {
+      int num = matrix[row][column];
+      if (num == target) {
+        return true;
+      } else if (target < num) {
+        column--;
+      } else {
+        row++;
+      }
+    }
+    return false;
+  }
+  // end::answer[]
+}