[Leetcode] [Java] Candy

Title:

There is N children standing in a line. Each child is assigned a rating value.

You is giving candies to these children subjected to the following requirements:

• Each child must has at least one candy.
• Children with a higher rating get more candies than their neighbors.

What's the minimum candies you must give?

Test Instructions:

n A child stands in a column. Every child has a score.

You assign these candies to these children according to the following rules:

1. Each child has at least one sugar.

2. Children with high scores have more candies than their neighbours ' children.

What is the minimum number of candies that you can separate?

Algorithm Analysis:

* According to test instructions, ideas can be as follows:

* Initialize array DP, array members are 1, each child assigns a candy first

* Traverse from left to right, if the first child is higher than the i-1 child, then dp[i] = dp[i-1] + 1

* Traverse from right to left, if I child is taller than 1 child and candy is less than i+1 candy, then dp[i] = dp[i + 1] + 1

* This idea realizes the algorithm complexity is O (n)

The overall idea is as follows reference blog http://blog.csdn.net/lanxu_yy/article/details/17752273

AC Code:

<span style= "Font-family:microsoft yahei;font-size:10px;" >public class solution{public    int Candy (int[] ratings)     {        if (ratings = = NULL | | ratings.length = = 0)            r Eturn 0;                    arraylist<integer> DP = new arraylist<integer> ();                for (int i = 0; i < ratings.length; i++)             Dp.add (i, 1);        for (int i = 1; i < ratings.length; i++)             if (Ratings[i] > ratings[i-1])                dp.set (i, Dp.get (i-1) + 1); 
   
    for (int i = ratings.length-2; I >= 0; i--)             if (Ratings[i] > ratings[i + 1] && dp.get (i) <= dp.ge T (i + 1))                 Dp.set (i, Dp.get (i + 1) + 1);        int res = 0;        for (int i = 0; i < dp.size (); i++)            res + = Dp.get (i);        return res;    }} </span>
   

Copyright NOTICE: This article is the original article of Bo Master, reprint annotated source

[Leetcode] [Java] Candy