135. Candy

class Solution {
public:
    int candy(vector<int>& ratings) {
        int n = ratings.size(); // Get the number of children
        
        vector<int> candies(n, 1); // Initialize a vector to store the number of candies for each child
        
        // First pass: Check ratings from left to right
        for(int i = 1; i < n; i++){
            if(ratings[i - 1] < ratings[i] && candies[i - 1] >= candies[i]){
                // If the current child has a higher rating and fewer or equal candies than the previous child,
                // give them one more candy than the previous child
                candies[i] = candies[i - 1] + 1;
            }
        }
        
        // Second pass: Check ratings from right to left
        for(int i = n - 2; i >= 0; i--){
            if(ratings[i + 1] < ratings[i] && candies[i + 1] >= candies[i]){
                // If the current child has a higher rating and fewer or equal candies than the next child,
                // give them one more candy than the next child
                candies[i] = candies[i + 1] + 1;
            }
        }
        
        int totalCandies = 0;
        
        // Calculate the total number of candies needed
        for(int i = 0; i < n; i++){
            totalCandies += candies[i];
        }
        
        return totalCandies;
    }
};