[1793] Adding Solution ofmaximum-score-of-a-good-subarray.java

Hard/maximum-score-of-a-good-subarray.java

@@ -0,0 +1,56 @@
+class Solution {
+    public int maximumScore(int[] nums, int k) {
+        int [] nsr = findNSR(nums);
+        int [] nsl = findNSL(nums);
+
+        int score =0;
+        for(int i=0;i<nums.length;i++){
+           int l = nsl[i];
+           int r = nsr[i];
+           if(l+1 <= k && r-1>= k){
+               score = Math.max(score,nums[i] *(r-l-1));
+           }
+        }
+        return score;
+    }
+
+//find next smaller element on right 
+    public int[] findNSR(int [] arr){
+        int [] nsr = new int[arr.length];
+        Stack<Integer> s = new Stack<>();
+        for(int i=arr.length-1;i>=0;i--){
+            while(!s.isEmpty() && arr[i] <= arr[s.peek()] ){
+                s.pop();
+            }
+            if(s.isEmpty()){
+                nsr[i] =arr.length;
+            }
+            else{
+                nsr[i] = s.peek();
+            }
+            s.push(i);
+        }
+        return nsr;
+
+    }
+        //find next smaller element on left 
+
+    public int[] findNSL(int [] arr){
+        int [] nsl = new int[arr.length];
+        Stack<Integer> s = new Stack<>();
+        for(int i=0;i<arr.length;i++){
+            while(!s.isEmpty() && arr[i] <= arr[s.peek()]){
+                s.pop();
+            }
+            if(s.isEmpty()){
+                nsl[i] =-1;
+            }
+            else{
+                nsl[i] = s.peek();
+            }
+            s.push(i);
+        }
+        return nsl;
+
+    }
+}