Two-Pointers-2

MergeSortedArray.java

@@ -0,0 +1,26 @@
+// Time Complexity :O(m+n)
+// Space Complexity :O(1)
+// Did this code successfully run on Leetcode :yes
+class Solution {
+    public void merge(int[] nums1, int m, int[] nums2, int n) {
+        int p1 = m-1;
+        int p2 = n-1;
+        int p3 = m+n-1;
+        while(p1 >= 0 && p2 >=0){
+            if(nums2[p2] > nums1[p1]){
+                nums1[p3] = nums2[p2];
+                p2--;
+            }else{
+                nums1[p3] = nums1[p1];
+                p1--;
+            }
+            p3--;
+        }
+        while(p2 >= 0){//copy rest of nums2 to nums1
+            nums1[p3] = nums2[p2];
+            p2--;
+            p3--;
+        }
+    }
+}
+

RemoveDuplicatesFromSortedArrayII.java

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+// Time Complexity :O(n)
+// Space Complexity :O(1)
+// Did this code successfully run on Leetcode :yes
+class Solution {
+    public int removeDuplicates(int[] nums) {
+        int k=2;
+        int p1=k;
+        int p2=k;
+        while(p2<nums.length){
+            if(nums[p1-k]!=nums[p2]){
+                nums[p1]=nums[p2];
+                p1++;
+            }
+            p2++;
+        }
+        return p1;
+    }
+}

SearchA2DMatrixII.java

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+// Time Complexity :O(m+n)
+// Space Complexity :O(1)
+// Did this code successfully run on Leetcode :yes
+class Solution {
+    public boolean searchMatrix(int[][] matrix, int target) {
+        int m = matrix.length;
+        int n = matrix[0].length;
+        int row = m - 1, col = 0;//bottom-left
+        while(row>=0 && col<n){
+            if(matrix[row][col] == target) return true;
+            else if(matrix[row][col] > target) row--;
+            else col++;
+        }
+        return false;
+    }
+}