java: add «2462. Total Cost to Hire K Workers»

Signed-off-by: Matej Focko <me@mfocko.xyz>

java/total-cost-to-hire-k-workers.java

@@ -0,0 +1,43 @@
+import java.util.Comparator;
+import java.util.PriorityQueue;
+
+class Solution {
+  private record Worker(int cost, int queue) {}
+
+  private static final Comparator<Worker> WORKER_CMP =
+      Comparator.comparing(Worker::cost).thenComparing(Worker::queue);
+
+  public long totalCost(int[] costs, int k, int candidates) {
+    var q = new PriorityQueue<Worker>(WORKER_CMP);
+
+    // Add left side
+    for (int i = 0; i < candidates; ++i) {
+      q.offer(new Worker(costs[i], 0));
+    }
+
+    // Add right side
+    for (int i = Math.max(candidates, costs.length - candidates); i < costs.length; ++i) {
+      q.offer(new Worker(costs[i], 1));
+    }
+
+    long cost = 0;
+
+    int l = candidates, r = costs.length - 1 - candidates;
+    for (int i = 0; i < k; ++i) {
+      var worker = q.poll();
+      cost += worker.cost();
+
+      if (l <= r) {
+        if (worker.queue() == 0) {
+          q.offer(new Worker(costs[l], 0));
+          ++l;
+        } else {
+          q.offer(new Worker(costs[r], 1));
+          --r;
+        }
+      }
+    }
+
+    return cost;
+  }
+}