Dynamic Programming - Candy - array

// Dynamic programming… usually this type question just need to loop from begin to end, update one time, then reverse the loop… update another time… consider this way for this type of problems.


public class Solution {
    public int candy(int[] ratings) {
        int[] candy = new int[ ratings.length ];
    //allocate candies, considering the minimal rating on the left
    candy[0] = 1;
    for(int i = 1; i < ratings.length; i++){
        candy[i] = ratings[i] > ratings[i-1] ? candy[i-1]+1 : 1;
    }
    //modify the allocation, considering the minimal rating on the right
    int totalCandy = candy[ratings.length-1];
    for(int i = ratings.length-2; i >= 0; i--){
        candy[i] = (ratings[i] > ratings[i+1] && candy[i+1] >= candy[i]) ? candy[i+1]+1 : candy[i]; //candy[i+1]+1 > candy[i])
        //count total candies by the way
        totalCandy += candy[i];
    }
    return totalCandy;
    }
}