update 801 java

leetcode_java/src/main/java/LeetCodeJava/DynamicProgramming/MinimumSwapsToMakeSequencesIncreasing.java

@@ -4,6 +4,43 @@
 
 import java.util.Arrays;
 
+/**
+ *  801. Minimum Swaps To Make Sequences Increasing
+ * Hard
+ * Topics
+ * Companies
+ * You are given two integer arrays of the same length nums1 and nums2. In one operation, you are allowed to swap nums1[i] with nums2[i].
+ *
+ * For example, if nums1 = [1,2,3,8], and nums2 = [5,6,7,4], you can swap the element at i = 3 to obtain nums1 = [1,2,3,4] and nums2 = [5,6,7,8].
+ * Return the minimum number of needed operations to make nums1 and nums2 strictly increasing. The test cases are generated so that the given input always makes it possible.
+ *
+ * An array arr is strictly increasing if and only if arr[0] < arr[1] < arr[2] < ... < arr[arr.length - 1].
+ *
+ *
+ *
+ * Example 1:
+ *
+ * Input: nums1 = [1,3,5,4], nums2 = [1,2,3,7]
+ * Output: 1
+ * Explanation:
+ * Swap nums1[3] and nums2[3]. Then the sequences are:
+ * nums1 = [1, 3, 5, 7] and nums2 = [1, 2, 3, 4]
+ * which are both strictly increasing.
+ * Example 2:
+ *
+ * Input: nums1 = [0,3,5,8,9], nums2 = [2,1,4,6,9]
+ * Output: 1
+ *
+ *
+ * Constraints:
+ *
+ * 2 <= nums1.length <= 105
+ * nums2.length == nums1.length
+ * 0 <= nums1[i], nums2[i] <= 2 * 105
+ *
+ *
+ */
+// NOTE : An array arr is strictly increasing if and only if arr[0] < arr[1] < arr[2] < ... < arr[arr.length - 1].
 public class MinimumSwapsToMakeSequencesIncreasing {
 
     // V0
@@ -104,12 +141,10 @@ public int solve(int nums1[], int nums2[], int ind, int[] dp) {
         if (ind == nums1.length) return 0;
 
         // Condition 1
-
         if (ind > 0 && (nums1[ind - 1] >= nums1[ind] || nums2[ind - 1] >= nums2[ind])) {
 
             //	nums1[] = [3,2]
             //	nums2[] = [1,4]
-
             int t = nums1[ind];
             nums1[ind] = nums2[ind];
             nums2[ind] = t;
@@ -120,7 +155,6 @@ public int solve(int nums1[], int nums2[], int ind, int[] dp) {
             // nums1[] = [3,4]
             // nums2[] = [1,2]
             // therefore we have to swap it back so that we can have our original array.
-
             t = nums1[ind];
             nums1[ind] = nums2[ind];
             nums2[ind] = t;
@@ -129,12 +163,10 @@ public int solve(int nums1[], int nums2[], int ind, int[] dp) {
 
         }
         // Condition 2
-
         else if (ind > 0 && (nums1[ind - 1] >= nums2[ind] || nums2[ind - 1] >= nums1[ind])) {
             return solve(nums1, nums2, ind + 1, dp);
         }
         // Condition 3
-
         else {
             if (dp[ind] != -1) return dp[ind];