LeetCode 135 : Candy

[LeetCode 135 : Candy](LeetCode 135 : Candy)

题目大意

• Description

 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? 

• 大意
  给排成一行的孩子分发糖果，每个孩子分配有一个值，每个孩子至少获得一个糖果，值大的孩子获得的糖果必须比周围的孩子获得的多，最少需要多少糖果？

代码

 int candy(vector<int> &ratings) {        int size = ratings.size();        vector<int> num(size,1);        int counter =0;        for(int i=0;i<size;i++){            if(ratings[i]>ratings[i-1]){                num[i] = num[i-1]+1;            }        }        for(int i=size-1;i>=0;i--){            if(ratings[i]<ratings[i-1] && num[i]>=num[i-1]){                num[i-1]=num[i]+1;            }            counter+=num[i];        }        return counter;    }

分析

定义一个整型数组num，长度与ratings数组相同，初始值均为1,。ratings数组先从前向后，每个元素与前一个相比，如果ratings值大则对应的num值等于前一个的加1，然后从后向前依次比，如果前一个元素的ratings值大于后一个的，同时它的num值不大于后一个的num值，其num值等于后一个的num值加一。