Candy

 Thereare N children standing in a line. Each child is assigned arating value.

You are giving candiesto 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 minimumcandies you must give?

思路：跟trapwater的思路比较像，就是每个item上的取值取决于左右两边，所以需要左右扫两遍。从左往右扫的时候如果item左边的比他大就置为最低1，如果比他小就+1，右边同理。每个item的值为左右的最大值。

Ref：http://www.cnblogs.com/springfor/p/3877120.html

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