[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。

 

 1 class Solution {

 2 public:

 3     int candy(vector<int> &ratings) {

 4         int res = 0;

 5         int n = ratings.size();

 6         if (n == 0) {

 7             return res;

 8         }

 9         int *t = new int[n];

10         for (int i = 0; i < n; ++i) {

11             t[i] = 1;

12         }

13         for (int i = 1; i < n; ++i) {

14             if (ratings[i] > ratings[i-1]) {

15                 t[i] = t[i-1] + 1;

16             }

17         }

18         for (int i = n - 1; i >= 1; --i) {

19             if (ratings[i] < ratings[i-1]) {

20                 t[i-1] = (t[i] + 1) > t[i-1] ? (t[i] + 1) : t[i-1];

21             }

22         }

23         for (int i = 0; i < n; ++i) {

24             res += t[i];

25         }

26         return res;

27     }

28 };