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?

分析：分糖果。每个小孩必须有一个糖果，ratings值大的孩子比他的邻居分得的糖果数要多。

自己在纸上画一画，从两边开始分别扫描，分段进行糖果分发。

从左边开始，假设可以找到x个连续递增的区间；从右边开始，假设可以找到y个连续递增的区间，那么答案就是x + y个区间糖果数量累加的结果。

用时：37ms

class Solution {
public:
    int candy(vector<int>& ratings) {
        vector<int> record(ratings.size(), 1);
        
        for(int i = 1, increase = 1; i < ratings.size(); i++){
            if(ratings[i] > ratings[i - 1]) record[i] = ++increase;
            else increase = 1;
        }
        
        for(int j = ratings.size() - 2, increase = 1; j >= 0; j--){
            if(ratings[j] > ratings[j + 1]) record[j] = max(++increase, record[j]);
            else increase = 1;
        }
        
        int result = 0;
        for(int i = 0; i < ratings.size(); i++) result += record[i];
        
        return result;
    }
};