sliding window

Author: Dhananjay Nagargoje

Diff for: src/main/java/problems/patterns/ontwopointerstrategy/DeleteMiddleOfList.java

@@ -1,4 +1,4 @@
-package problems.ontwopointerstrategy;
+package problems.patterns.ontwopointerstrategy;
 
 import datastructures.linkedlist.Node;
 

Diff for: src/main/java/problems/patterns/slidingwindows/LongestRepeatingCharacterReplacement.java

@@ -1,7 +1,6 @@
 package problems.patterns.slidingwindows;
 
 public class LongestRepeatingCharacterReplacement {
-    public int characterReplacement(String s, int k) {
         public int characterReplacement(String s, int k) {
             int len = s.length();
             int[] count = new int[26];
@@ -16,5 +15,40 @@ public int characterReplacement(String s, int k) {
             }
             return maxLength;
         }
-    }
+
+    /**
+     * Given a string s that consists of only uppercase English letters, you can perform at most k operations on that string.
+     *
+     * In one operation, you can choose any character of the string and change it to any other uppercase English character.
+     *
+     * Find the length of the longest sub-string containing all repeating letters you can get after performing the above operations.
+     *
+     * Note:
+     * Both the string's length and k will not exceed 104.
+     *
+     * Example 1:
+     *
+     * Input:
+     * s = "ABAB", k = 2
+     *
+     * Output:
+     * 4
+     *
+     * Explanation:
+     * Replace the two 'A's with two 'B's or vice versa.
+     *
+     *
+     * Example 2:
+     *
+     * Input:
+     * s = "AABABBA", k = 1
+     *
+     * Output:
+     * 4
+     *
+     * Explanation:
+     * Replace the one 'A' in the middle with 'B' and form "AABBBBA".
+     * The substring "BBBB" has the longest repeating letters, which is 4.
+     *
+     */
 }

Diff for: src/main/java/problems/patterns/slidingwindows/MaxInEachWIndow.java

@@ -1,4 +1,40 @@
 package problems.patterns.slidingwindows;
 
+import edu.princeton.cs.algs4.In;
+
+import java.util.*;
+
 public class MaxInEachWIndow {
+    // DO NOT MODIFY THE LIST. IT IS READ ONLY
+    public static ArrayList<Integer> slidingMaximum(final List<Integer> A, int B) {
+        Deque<Integer> maxInWindow = new LinkedList<>();
+        ArrayList<Integer> result  =  new ArrayList<>();
+        for (int i=0;i<A.size();i++) {
+            if (maxInWindow.size() == 0) {
+                maxInWindow.addLast(A.get(i));
+            }
+            else if (maxInWindow.size() >0 && maxInWindow.peekLast() < A.get(i)) {
+                while (maxInWindow.size() >0 && maxInWindow.peekLast() < A.get(i)) {
+                    maxInWindow.removeLast();
+                }
+                maxInWindow.addLast(A.get(i));
+            } else {
+                maxInWindow.addLast(A.get(i));
+            }
+            if (i >= B-1) {
+                result.add(maxInWindow.peekFirst());
+                if (A.get(i+1-B).equals(maxInWindow.peekFirst())) {
+                    maxInWindow.removeFirst();
+                }
+            }
+        }
+        return result;
+
+    }
+
+    public static void main(String[] args) {
+        List<Integer> sample = Arrays.asList(648, 614, 490, 138, 657, 544, 745, 582, 738, 229, 775, 665, 876, 448, 4, 81, 807, 578, 712, 951, 867, 328, 308, 440, 542, 178, 637, 446, 882, 760, 354, 523, 935, 277, 158, 698, 536, 165, 892, 327, 574, 516, 36, 705, 900, 482, 558, 937, 207, 368 );
+        System.out.println(slidingMaximum(sample, 9));
+    }
+
 }