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?
Constraints
Approach
Links
GeeksforGeeks
Examples
Input: [1, 0, 2]
Output: 5
Explanation: You can allocate to the first, second and third child with 2, 1, 2 candies respectively.
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.
Solutions
/**
* Time complexity :
* Space complexity :
*/
class Solution {
public int candy(int[] ratings) {
if(ratings.length == 0) return 0;
int n = ratings.length;
int[] arrLtoR = new int[n];
int[] arrRtoL = new int[n];
arrLtoR[0] = 1;
arrRtoL[n-1] = 1;
for(int i = 1; i < n; i++) {
arrLtoR[i] = (ratings[i-1] < ratings[i])? arrLtoR[i-1]+1: 1;
arrRtoL[n-i-1] = (ratings[n-i-1] > ratings[n-i])? arrRtoL[n-i]+1: 1;
}
int total = 0;
for(int i = 0; i < n; i++) {
total += Math.max(arrLtoR[i], arrRtoL[i]);
}
return total;
}
}