Java for LeetCode 135 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?

解题思路：

双向爬坡问题，从前往后、从后往前各扫一遍，JAVA实现如下：

	public int candy(int[] ratings) {
		int sum = 0;
		int[] candies = new int[ratings.length];
		for (int i = 0; i < ratings.length - 1; i++)
			if (ratings[i] < ratings[i + 1])
				candies[i + 1] = candies[i] + 1;
		for (int i = ratings.length - 2; i >= 0; i--)
			if (ratings[i + 1] < ratings[i])
				candies[i] = Math.max(candies[i], candies[i + 1] + 1);
		for (int i = 0; i < candies.length; i++)
			sum += 1 + candies[i];
		return sum;
	}