leetcode之candy

题目：
There are N children standing ina line. Each child is assigned a rating value.
You are giving candies to these childrensubjected to the following requirements:
Each child musthave at least one candy.
Children with ahigher rating get more candies than their neighbors.
What is the minimum candies you must give?
思路：
用一个数组 candy
，表示第i
个小孩所应该发的最少糖果数。
数组 ratings

表示每个小孩的评分。
1.     从左到右扫描一遍，

candy[i] = 1, 
 if ratings[i] <= ratings[i-1] ;

candy[i] = candy[i-1] + 1,
  if ratings[i] > ratings[i-1]
2.     从右到左扫描一遍，

candy[i] = candy[i],
  if ratings[i] <= ratings[i+1] ;

candy[i] = max(candy[i], candy[i+1] + 1),
  if ratings[i] > ratings[i+1]
解法：
动态规划
复杂度：
   
时间：时间 O(n)，空间
O(n)
实现：
public int candy(int[] ratings){
             
intsize=ratings.length;
             
if(size<=1)return size;
             
int[]nums=new int[size];
             
for(inti=0;i<size;i++){
            nums[i]=1;
             
}
             
for(intj=1;j<size;j++){
                    
if(ratings[j]>ratings[j-1])nums[j]=nums[j-1]+1;
             
}
             
for(intm=size-1;m>0;m--){
                    
if(ratings[m-1]>ratings[m]){
                           
nums[m-1]=Math.max(nums[m]+1,nums[m-1]);
                    
}
             
}
             
intresult=0;
             
for(intn=0;n<size;n++){
                    
result+=nums
;
             
}
             

             
returnresult;
 
      
}