FB面经 Prepare: Task Schedule

tasks has cooldown time, give an input task id array, output finish time
input: AABCA
A--ABCA
output:7

 package fb;

 import java.util.*;

 public class Scheduler {

     public int task(int[] tasks, int cooldown) {
         int time = 0;
         HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();

         StringBuilder output = new StringBuilder();

         for (int i=0; i<tasks.length; i++) {
             if (!map.containsKey(tasks[i]) || time>=map.get(tasks[i])) {
                 map.put(tasks[i], time+cooldown);
                 time++;

                 output.append(tasks[i]);
             }
             else { // time < map.get(tasks[i])
                 for (int k=time; k<map.get(tasks[i]); k++) {
                     output.append("-");
                 }

                 time = map.get(tasks[i]);
                 map.put(tasks[i], time+cooldown);
                 time++;

                 output.append(tasks[i]);
             }
         }
         return time;
     }

     public static void main(String[] args) {
         Scheduler sc = new Scheduler();
         //int res = sc.task(new int[]{1,1,2,3,1}, 3);
         int res = sc.task(new int[]{1,2,1,2,3}, 3);
         //String output = sc.task(new int[]{1,2,2,1,3}, 3);
         System.out.println(res);
         //System.out.println(output);
     }
 }