java: add «88. Merge Sorted Array»

URL:	https://leetcode.com/problems/merge-sorted-array/

java/merge-sorted-array.java

@@ -0,0 +1,25 @@
+class Solution {
+  public void merge(int[] nums1, int m, int[] nums2, int n) {
+    // Shift numbers to right
+    for (int i = m - 1, k = nums1.length - 1; i >= 0; --i, --k) {
+      nums1[k] = nums1[i];
+    }
+
+    // Merge them
+    int j = 0, k = 0;
+    for (int i = nums1.length - m; i < nums1.length && j < n; ++k) {
+      if (nums1[i] < nums2[j]) {
+        nums1[k] = nums1[i];
+        ++i;
+      } else {
+        nums1[k] = nums2[j];
+        ++j;
+      }
+    }
+
+    // Add the remainder
+    for (; j < n; ++j, ++k) {
+      nums1[k] = nums2[j];
+    }
+  }
+}