Candy

题目

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?

方法

假设是递增的，每次进行加一操作，就可以。

假设是相等，从一開始。

假设是递减的，要保证增上去的够减，否则要加一。本质：将递减也按递增来处理，从1開始，直到不够减的时候进行加1.

    public int candy(int[] ratings) {
        if (ratings == null || ratings.length == 0) {
        	return 0;
        }
        
        int len = ratings.length;
        int sum = 1;
        int curDecrease = 1;
        int curIncrease = 1;
        int left = 0;
        boolean flag = true;
        for (int i = 1; i < len; i++) {
        	if (ratings[i] > ratings[i - 1]) {
        		if (!flag) {
        			curIncrease = 1;
        			flag = true;
        		}
        		curIncrease++;
        		sum += curIncrease;
        		left = i;
        		curDecrease = 1;
        	} else if (ratings[i] == ratings[i - 1]) {
        		sum += 1;
        		curIncrease = 1;
        		curDecrease = 1;
        		left = i;
        	} else {
        		if (i - left >= curIncrease) {
        			sum = sum + 1;
        		}
        		sum += curDecrease;
        		curDecrease++;
        		flag = false;
        	}
        }
        return sum;
    }