Create 1642-furthest-building-you-can-reach.java

Author: sujal-goswami

java/1642-furthest-building-you-can-reach.java

@@ -0,0 +1,43 @@
+/*            Max Heap Method
+  ----------------------------------------*/
+class Solution {
+    public int furthestBuilding(int[] heights, int bricks, int ladders) {
+        PriorityQueue<Integer> pq = new PriorityQueue<>((a, b) -> b - a);
+        for (int i = 0; i < heights.length - 1; i++) {
+            int diff = heights[i + 1] - heights[i];
+            
+            if (diff <= 0)
+                continue;
+
+            bricks -= diff;
+            pq.add(diff);
+
+            if(bricks < 0){
+                if(ladders == 0)
+                    return i;
+                ladders -= 1; 
+                bricks += pq.poll();   
+            }
+        }
+        return heights.length - 1;
+    }
+}
+
+/*                Min Heap Method
+  -----------------------------------------------*/
+class Solution {
+    public int furthestBuilding(int[] heights, int bricks, int ladders) {
+        PriorityQueue<Integer> pq = new PriorityQueue<>();
+        for(int i = 0; i < heights.length-1; i++){
+            int diff = heights[i + 1] - heights[i];
+            if(diff < 0)
+                continue;
+            pq.add(diff);
+            if(pq.size() > ladders)
+                bricks -= pq.poll();
+            if(bricks < 0)
+                return i;        
+        }
+        return heights.length - 1;
+    }
+}