[Leetcode] 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?

 

先从左向右扫描一遍，如果当前小盆宇比左边的小盆宇评分高，就多给他一颗糖，然后再从右向左扫描一遍。

 

class Solution {
public:
    int candy(vector<int> &ratings) {
        int res = 0;
        int n = ratings.size();
        if (n == 0) {
            return res;
        }
        int *t = new int[n];
        for (int i = 0; i < n; ++i) {
            t[i] = 1;
        }
        for (int i = 1; i < n; ++i) {
            if (ratings[i] > ratings[i-1]) {
                t[i] = t[i-1] + 1;
            }
        }
        for (int i = n - 1; i >= 1; --i) {
            if (ratings[i] < ratings[i-1]) {
                t[i-1] = (t[i] + 1) > t[i-1] ? (t[i] + 1) : t[i-1];
            }
        }
        for (int i = 0; i < n; ++i) {
            res += t[i];
        }
        return res;
    }
};