Leetcode-Candy

There are N children standing in a line. Each child is assigned a rating value.

You are giving candies to these children subjected to the following requirements:

Each child must have at least one candy.
Children with a higher rating get more candies than their neighbors.

What is the minimum candies you must give?

Solution:

 1 public class Solution {
 2     public int candy(int[] ratings) {
 3         int[] num = new int[ratings.length];
 4         Arrays.fill(num,1);
 5         for (int i=1;i<ratings.length;i++)
 6             if (ratings[i]>ratings[i-1]) num[i] = num[i-1]+1;
 7  
 8         for (int i=ratings.length-2;i>=0;i--)
 9             if (ratings[i]>ratings[i+1] && num[i]<=num[i+1]) 
10                 num[i] = num[i+1]+1;
11 
12         int sum = 0;
13         for (int i=0;i<ratings.length;i++) sum += num[i];
14 
15         return sum;        
16     }
17 }