leetcode:candy

题目描述:

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：

1. 这道题抓住关键信息，即只需要关注相邻元素之间的大小即可
2. 首先，申请一个临时数组，对应着比例数组中的每个元素，同时初始化为每个元素赋值为 1
3. 第一次遍历：从左向右，若相邻两个元素的后面一个元素权值大于前面一个，则令它加 1
4. 第二次遍历：从右向左，具体操作同步骤 3

代码如下：

 public int candy(int[] ratings) {
        int [] res = new int [ratings.length];

        for(int i = 0; i < res.length; i++){
            res[i] = 1;
        }

        for(int i = 1; i < ratings.length; i++){
            if(ratings[i] > ratings[i - 1]) res[i] = res[i - 1] + 1;
        }

        for(int i = ratings.length - 1; i > 0; i--){
            if(ratings[i - 1] > ratings[i] && res[i - 1] <= res[i]){
                res[i - 1] = res[i] + 1;
            }
        }

        for(int  i = 1; i < res.length; i++){
                res[0] += res[i];
        }
        return res[0];
    }

转载于:https://my.oschina.net/happywe/blog/3079800