Minimize the Maximum Adjacent Element Difference

Author: Goutham Vidya Pradhan

README.md

@@ -103,6 +103,7 @@ My accepted leetcode solutions to some of the common interview problems.
 - ![#f03c15](https://placehold.it/15/f03c15/000000?text=+) [Minimum Window Subsequence](src/main/java/binary_search/MinimumWindowSubsequence.java) (Hard)
 - ![#f03c15](https://placehold.it/15/f03c15/000000?text=+) [Koko Eating Bananas](src/main/java/binary_search/KokoEatingBananas.java) (Hard)
 - [Single Element in a Sorted Array](src/main/java/binary_search/SingleElementInASortedArray.java) (Medium)
+- ![#f03c15](https://placehold.it/15/f03c15/000000?text=+) [Minimize the Maximum Adjacent Element Difference](src/main/java/binary_search/MinimizeTheMaximumAdjacentElementDifference.java) (Hard)
 
 #### [Bit Manipulation](src/main/java/bit_manipulation)
 

build.gradle

@@ -1,10 +1,10 @@
 plugins {
     id 'java'
-    id 'com.github.sherter.google-java-format' version '0.8'
+    id 'com.github.sherter.google-java-format' version '0.9'
 }
 
 dependencies {
-    implementation 'com.google.googlejavaformat:google-java-format:1.12.0'
+    implementation 'com.google.googlejavaformat:google-java-format:1.8.0'
 }
 
 repositories {

src/main/java/binary_search/MinimizeTheMaximumAdjacentElementDifference.java

@@ -0,0 +1,107 @@
+package binary_search;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class MinimizeTheMaximumAdjacentElementDifference {
+    record Interval(int s, int e, boolean hasMoreThanOne){
+        static boolean check(int a, int mid, int b, int range){
+            return Math.abs(mid - a) <= range && Math.abs(mid - b) <= range;
+        }
+        static boolean check(int a, int mid1, int mid2, int b, int range){
+            return Math.abs(mid1 - a) <= range && Math.abs(mid1 - mid2) <= range && Math.abs(mid2 - b) <= range;
+        }
+    }
+
+    public static void main(String[] args) {
+        int[] nums = new int[]{-1,10,-1,8};
+        int res = new MinimizeTheMaximumAdjacentElementDifference().minDifference(nums);
+        System.out.println(res);
+    }
+
+    public int minDifference(int[] nums) {
+        boolean noPositiveNum = Arrays.stream(nums).filter(i -> i != -1).findAny().isEmpty();
+        if(noPositiveNum){
+            return 0;
+        }
+        int currentMax = getCurrentMax(nums);
+        List<Interval> intervals = buildIntervals(nums);
+        int minStart = Integer.MAX_VALUE, maxEnd = Integer.MIN_VALUE;
+        for (Interval interval : intervals) {
+            minStart = Math.min(minStart, Math.min(interval.e, interval.s));
+            maxEnd = Math.max(maxEnd, Math.max(interval.e, interval.s));
+        }
+        int l = 0, h = maxEnd, m;
+        int ans = -1;
+        while(l <= h){
+            m = l + (h - l) / 2;
+            boolean result = checkIfThisNumberSatisfiesAllIntervals(intervals, minStart + m, maxEnd - m, m);
+            if(result){
+                ans = m;
+                h = m - 1;
+            } else {
+                l = m + 1;
+            }
+        }
+        return Math.max(ans, currentMax);
+    }
+
+    private int getCurrentMax(int[] nums){
+        int currMax = Integer.MIN_VALUE;
+        int previous = nums[0];
+        for(int i = 1; i < nums.length; i ++){
+            if(nums[i] != -1){
+                if(previous != -1){
+                    currMax = Math.max(currMax, Math.abs(previous - nums[i]));
+                }
+                previous = nums[i];
+            } else {
+                previous = -1;
+            }
+        }
+        return currMax;
+    }
+
+    private List<Interval> buildIntervals(int[] nums) {
+        int previous = -1;
+        int minusOneCount = 0;
+        List<Interval> intervals = new ArrayList<>();
+        for (int num : nums) {
+            if (num == -1) {
+                minusOneCount ++;
+            } else {
+                if (minusOneCount > 0) {
+                    intervals.add(new Interval(previous != -1 ? previous : num, num, minusOneCount > 1));
+                    minusOneCount = 0;
+                }
+                previous = num;
+            }
+        }
+        if(nums[nums.length - 1] == -1){
+            intervals.add(new Interval(previous, previous, minusOneCount > 1));
+        }
+        return intervals;
+    }
+
+    boolean checkIfThisNumberSatisfiesAllIntervals(List<Interval> intervals, int minStart, int maxEnd, int maxDiff){
+        for (Interval interval : intervals) {
+            if (interval.hasMoreThanOne) {
+                boolean res1 = Interval.check(interval.s, minStart, minStart, interval.e, maxDiff);
+                boolean res2 = Interval.check(interval.s, minStart, maxEnd, interval.e, maxDiff);
+                boolean res3 = Interval.check(interval.s, maxEnd, minStart, interval.e, maxDiff);
+                boolean res4 = Interval.check(interval.s, maxEnd, maxEnd, interval.e, maxDiff);
+                if (!res1 && !res2 && !res3 && !res4) {
+                    return false;
+                }
+            } else {
+                boolean res1 = Interval.check(interval.s, minStart, interval.e, maxDiff);
+                boolean res2 = Interval.check(interval.s, maxEnd, interval.e, maxDiff);
+                if (!res1 && !res2) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+}