Create QueueReconstructionByHeight.java

Author: Trmpsanjay

QueueReconstructionByHeight.java

@@ -0,0 +1,28 @@
+import java.util.ArrayList;
+class Solution {
+    public int[][] reconstructQueue(int[][] people) {
+        /*
+        Algorithm:
+        First sort all the people in decreasing order of their height.for those wo have same height  sort them
+        in ascending order of  their k values
+        Now simply iterate over the sorted array and insert them in the output array at kth index;
+        
+        */
+        
+        Arrays.sort(people,(a,b) -> a[0]==b[0] ? a[1]-b[1] : b[0]-a[0]); // this means we will sort arrays based
+            //on lambda expresiion/comparator a and b if a[0]==b[0] then we are going to return a[1]-b[1] else 
+            // we will return b[0]-a[0];
+            
+            // creating a arraylist
+        ArrayList<int[]> result = new ArrayList<>();
+        // iterating in the array and putting them at index k
+        for(int [] p : people){  // for each loop
+            result.add(p[1],p);   // p[1] = kth index
+        }
+        // returning the arraylist converting into array
+        int ans[][] =  result.toArray(new int[people.length][2]);
+       
+        return ans;
+        
+    }
+}