Candy | Leetcode 135

class Solution {
public:
    int candy(vector<int>& ratings) {
        int n=ratings.size();
        vector<int> candies(n,1);

        //Step-1: Assign increasing curve with increasing candies
        for(int i=1;i<n;++i){
            if(ratings[i]>ratings[i-1])
                candies[i] = 1 + candies[i-1];
        }

        //Step-2: Assign decreasing curve with increasing candies
        int total = candies[n-1];
        for(int i=n-1;i>0;--i){
            if(ratings[i-1]>ratings[i])
                candies[i-1] = max(candies[i-1],1+candies[i]);
            total += candies[i-1];
        }
        return total;
    }
};
/*
//JAVA
import java.util.Arrays;

class Solution {
    public int candy(int[] ratings) {
        int n = ratings.length;
        int[] candies = new int[n];
        Arrays.fill(candies, 1);
        
        // Step-1: Assign increasing curve with increasing candies
        for (int i = 1; i < n; ++i) {
            if (ratings[i] > ratings[i-1]) {
                candies[i] = 1 + candies[i-1];
            }
        }
        
        // Step-2: Assign decreasing curve with increasing candies
        int total = candies[n-1];
        for (int i = n-1; i > 0; --i) {
            if (ratings[i-1] > ratings[i]) {
                candies[i-1] = Math.max(candies[i-1], 1 + candies[i]);
            }
            total += candies[i-1];
        }
        
        return total;
    }
}

#Python
class Solution:
    def candy(self, ratings: List[int]) -> int:
        n = len(ratings)
        candies = [1] * n
        
        # Step-1: Assign increasing curve with increasing candies
        for i in range(1, n):
            if ratings[i] > ratings[i-1]:
                candies[i] = 1 + candies[i-1]
        
        # Step-2: Assign decreasing curve with increasing candies
        total = candies[-1]
        for i in range(n-1, 0, -1):
            if ratings[i-1] > ratings[i]:
                candies[i-1] = max(candies[i-1], 1 + candies[i])
            total += candies[i-1]
        
        return total
*/