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?

Example 1:

1 2 3

Input: [1,0,2] Output: 5 Explanation: You can allocate to the first, second and third child with 2, 1, 2 candies respectively.

Example 2:

1 2 3 4

Input: [1,2,2] Output: 4 Explanation: You can allocate to the first, second and third child with 1, 2, 1 candies respectively. The third child gets 1 candy because it satisfies the above two conditions.

Solution

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classSolution { public: intcandy(vector<int>& ratings){ vector<int> candy(ratings.size(), 1); for(int i = 1; i < ratings.size(); i++) if(ratings[i] > ratings[i-1]) candy[i] = candy[i-1] + 1; for(int i = ratings.size()-1; i >= 1; i--) if(ratings[i-1] > ratings[i]) candy[i-1] = max(candy[i-1], candy[i] + 1); int res = 0; for(auto it : candy) res += it; return res; } };