Time: 337 ms (68.91%) | Memory: 105.9 MB (6.74%) - LeetSync

Author: tushar-upadhya

1917-maximum-average-pass-ratio/maximum-average-pass-ratio.java

@@ -0,0 +1,42 @@
+class Solution {
+    public double maxAverageRatio(int[][] classes, int extraStudents) {
+        int n = classes.length;
+
+        // Priority queue to act as a max-heap, storing pairs of {max-delta, index}
+        PriorityQueue<double[]> pq = new PriorityQueue<>((a, b) -> Double.compare(b[0], a[0]));
+
+        // Initialize the priority queue with the delta values and indices
+        for (int i = 0; i < n; i++) {
+            double currentPR = (double) classes[i][0] / classes[i][1];
+            double newPR = (double) (classes[i][0] + 1) / (classes[i][1] + 1);
+            double delta = newPR - currentPR;
+            pq.offer(new double[]{delta, i});
+        }
+
+        // Allocate extra students
+        while (extraStudents-- > 0) {
+            // Extract the class with the maximum delta
+            double[] current = pq.poll();
+            int index = (int) current[1];
+
+            // Update the class with an extra student
+            classes[index][0]++;
+            classes[index][1]++;
+
+            // Recalculate the delta for this class
+            double currentPR = (double) classes[index][0] / classes[index][1];
+            double newPR = (double) (classes[index][0] + 1) / (classes[index][1] + 1);
+            double delta = newPR - currentPR;
+
+            // Push the updated delta and index back into the priority queue
+            pq.offer(new double[]{delta, index});
+        }
+        
+        // Calculate the final average pass ratio
+        double result = 0.0;
+        for (int i = 0; i < n; i++) {
+            result += (double) classes[i][0] / classes[i][1];
+        }
+        return result / n;
+    }
+}