Candy – LeetCode Solution Java , Python 3, Python 2 , C , C++, Best and Optimal Solutions , All you need.

There are n children standing in a line. Each child is assigned a rating value given in the integer array ratings.

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.

Return the minimum number of candies you need to have to distribute the candies to the children.

Example 1:

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

Example 2:

Input: ratings = [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.

Constraints:

• n == ratings.length
• 1 <= n <= 2 * 104
• 0 <= ratings[i] <= 2 * 104

C++ Candy LeetCode Solution

class Solution {
public:
    int candy(vector<int>& ratings) {
        
        int s = 0;
        int n = ratings.size();
        vector<int> left(n, 1);
        vector<int> right(n, 1);
        
        for(int i=1; i<n; i++){
            if(ratings[i] > ratings[i-1]){
                left[i] = left[i-1]+1;
            }
        }

        for(int i=n-2; i>=0; i--){
            if(ratings[i] > ratings[i+1]){
                right[i] = right[i+1]+1;
            }
        }
        
        int sum = 0;
        for(int i=0; i<n; i++){
            sum += max(left[i], right[i]);
        }
        return sum;
        
    }
};

Java Candy LeetCode Solution

 public int candy(int[] ratings) {
    int [] candies=new int[ratings.length];
    Arrays.fill(candies,1);
    int back=ratings.length-1;
    //Scanning left side ratings of each child
    for(int i=1;i<ratings.length;i++)
    {
        if(ratings[i]>ratings[i-1])
        {
            candies[i]=candies[i-1]+1;    
        }
    }
     //Scanning right side ratings of each child
    for(int i=ratings.length-2;i>=0;i--)
    {
        if(ratings[i]>ratings[i+1])
        {
            candies[i]=Math.max(candies[i],candies[i+1]+1);
        }
    }
    int totalCandies=0;
    //calculating total candies from candies Array
    for(int candie:candies)
    {
        totalCandies+=candie;  
    }
    return totalCandies;
}
 

Python 3 Candy LeetCode Solution

 candies=[1]*len(ratings)
        if len(ratings)==1:
            return 1
        for i in range(1,len(ratings)):
            if ratings[i]>ratings[i-1] and candies[i]<=candies[i-1]:
                candies[i]=candies[i-1]+1
        for j in range(len(ratings)-2,-1,-1):
            if ratings[j]>ratings[j+1] and candies[j]<=candies[j+1]:
                candies[j]=candies[j+1]+1
        return sum(candies)

Array-1180
String-562
Hash Table-412
Dynamic Programming-390
Math-368
Sorting-264
Greedy-257
Depth-First Search-256
Database-215
Breadth-First Search-200
Tree-195
Binary Search-191
Matrix-176
Binary Tree-160
Two Pointers-151
Bit Manipulation-140
Stack-133
Heap (Priority Queue)-117
Design-116
Graph-108
Simulation-103
Prefix Sum-96
Backtracking-92
Counting-86
Sliding Window-73
Linked List-69
Union Find-66
Ordered Set-48
Monotonic Stack-47
Recursion-43
Trie-41
Binary Search Tree-40
Divide and Conquer-40
Enumeration-39
Bitmask-37
Queue-33
Memoization-32
Topological Sort-31
Geometry-30
Segment Tree-27
Game Theory-24
Hash Function-24
Binary Indexed Tree-21
Interactive-18
Data Stream-17
String Matching-17
Rolling Hash-17
Shortest Path-16
Number Theory-16
Combinatorics-15
Randomized-12
Monotonic Queue-9
Iterator-9
Merge Sort-9
Concurrency-9
Doubly-Linked List-8
Brainteaser-8
Probability and Statistics-7
Quickselect-7
Bucket Sort-6
Suffix Array-6
Minimum Spanning Tree-5
Counting Sort-5
Shell-4
Line Sweep-4
Reservoir Sampling-4
Eulerian Circuit-3
Radix Sort-3
Strongly Connected Componen-t2
Rejection Sampling-2
Biconnected Component-1

Leave a comment below

Related posts:

Add Two Numbers- LeetCode Solution Search in Rotated Sorted Array – LeetCode Solution Permutations II – LeetCode Solution Largest Rectangle in Histogram – LeetCode Solution Triangle – LeetCode Solution Longest Consecutive Sequence – LeetCode Solution