merge two sorted list

src/main/java/git/snippet/leetcode/LeetCode_0088_MergeSortedArray.java

-package git.snippet.leetcode;
-
-// Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
-//
-// Note:
-//
-// The number of elements initialized in nums1 and nums2 are m and n respectively.
-// You may assume that nums1 has enough space (size that is equal to m + n) to hold additional
-// elements from nums2.
-// Example:
-//
-// Input:
-// nums1 = [1,2,3,0,0,0], m = 3
-// nums2 = [2,5,6], n = 3
-//
-// Output: [1,2,2,3,5,6]
-//
-//
-// Constraints:
-//
-// -10^9 <= nums1[i], nums2[i] <= 10^9
-// nums1.length == m + n
-// nums2.length == n
-// https://leetcode.cn/problems/merge-sorted-array/
-// 笔记：
-public class LeetCode_0088_MergeSortedArray {
-
-    // 从尾部开始处理
-    public void merge(int[] nums1, int m, int[] nums2, int n) {
-        int len = m + n;
-        while (m > 0 && n > 0) {
-            if (nums1[m - 1] > nums2[n - 1]) {
-                nums1[--len] = nums1[--m];
-            } else {
-                nums1[--len] = nums2[--n];
-            }
-        }
-        while (n > 0) {
-            nums1[--len] = nums2[--n];
-        }
-    }
-}

src/main/java/git/snippet/mergesort/LeetCode_0088_MergeSortedArray.java

+package git.snippet.mergesort;
+
+// 合并两个有序数组
+// https://leetcode.com/problems/merge-sorted-array/
+// 笔记：https://www.cnblogs.com/greyzeng/p/16653063.html
+
+/**
+ * @see LintCode_0006_MergeTwoSortedArrays
+ */
+public class LeetCode_0088_MergeSortedArray {
+    // 逆向遍历
+    // 谁大到最后一个位置
+    // 依次递减
+    public void merge(int[] nums1, int m, int[] nums2, int n) {
+        int i = m - 1;
+        int j = n - 1;
+        int index = m + n - 1;
+        while (i >= 0 && j >= 0) {
+            nums1[index--] = nums1[i] < nums2[j] ? nums2[j--] : nums1[i--];
+        }
+        while (j >= 0) {
+            // 只需要继续判断 nums2 了
+            // 因为 nums1 自然拍好了
+            nums1[index--] = nums2[j--];
+        }
+    }
+}

src/main/java/git/snippet/binarysearch/LintCode_0006_MergeTwoSortedArrays.java → src/main/java/git/snippet/mergesort/LintCode_0006_MergeTwoSortedArrays.java

-package git.snippet.binarysearch;
+package git.snippet.mergesort;
 
 // How can you optimize your algorithm if one array is very large and the other is very small?
 // https://www.lintcode.com/problem/6/
 // 笔记：https://www.cnblogs.com/greyzeng/p/16653063.html
 public class LintCode_0006_MergeTwoSortedArrays {
     // 常规解法
+    // 借鉴归并排序方法
     public static int[] mergeSortedArray1(int[] A, int[] B) {
         int m = A.length;
         int n = B.length;
@@ -13,11 +14,7 @@ public class LintCode_0006_MergeTwoSortedArrays {
         int j = 0;
         int index = 0;
         while (i < m && j < n) {
-            if (A[i] > B[j]) {
-                res[index++] = B[j++];
-            } else {
-                res[index++] = A[i++];
-            }
+            res[index++] = A[i] > B[j] ? B[j++] : A[i++];
         }
         while (i < m) {
             res[index++] = A[i++];