两次遍历,第一遍将大于等于序列的糖果分好,第二遍反向遍历,将小于序列的糖果分好
需要注意两点
1. 等于的情况,后一个孩子的糖果为1
2. 反向遍历的时候,到已经分了糖果的边界孩子时,需要判断,反向自增的糖果和此孩子之前分的糖果哪个大,取大值
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class="java" name="code">public class Solution { public int candy(int[] ratings) { if(ratings == null || ratings.length == 0){ return 0; } int count = 0; Integer[] counter = new Integer[ratings.length]; counter[0]=1; for(int i=1; i<ratings.length; i++){ Integer pre =ratings[i-1]; int num = ratings[i]; if(num>pre){ if(counter[i-1] == null){ counter[i]=2; }else { counter[i]=counter[i-1]+1; } }else if(num == pre){ counter[i] = 1; } } Integer firstNullIndex = null; for(int i=ratings.length-1; i>=0; i--){ if(counter[i] == null && firstNullIndex==null){ counter[i]=1; firstNullIndex = i; }else if(counter[i]==null && firstNullIndex!=null){ counter[i]=counter[i+1]+1; }else if(counter[i] != null && firstNullIndex!=null){ firstNullIndex = null; counter[i]=((counter[i+1]+1)>counter[i])?counter[i+1]+1:counter[i]; } } for(Integer c : counter){ if(c != null){ count += c; } } return count; } }
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