1776. car fleet ii

Java/CarFleetII.java

@@ -0,0 +1,28 @@
+class Solution {
+    public double[] getCollisionTimes(int[][] cars) {
+        int length = cars.length;
+        double[] times = new double[length];
+        Deque<Integer> stack = new LinkedList<Integer>();
+        for (int i = length - 1; i >= 0; i--) {
+            while (!stack.isEmpty()) {
+                if (cars[stack.peek()][1] >= cars[i][1])
+                    stack.pop();
+                else {
+                    if (times[stack.peek()] < 0)
+                        break;
+                    double time = times[stack.peek()] * (cars[i][1] - cars[stack.peek()][1]);
+                    if (time > cars[stack.peek()][0] - cars[i][0])
+                        break;
+                    else
+                        stack.pop();
+                }
+            }
+            if (stack.isEmpty())
+                times[i] = -1;
+            else
+                times[i] = (double) (cars[stack.peek()][0] - cars[i][0]) / (cars[i][1] - cars[stack.peek()][1]);
+            stack.push(i);
+        }
+        return times;
+    }
+}