Candy

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?

#include <iostream>#include <vector>#include <algorithm>using namespace std;class Solution{public:    int candy(vector<int> &ratings)    {        const int n = ratings.size();        vector<int> candy(n);        for (int i=1,inc = 1; i < n; ++i)   //从左到右        {            if (ratings[i-1] < ratings[i])                candy[i] = max(inc++,candy[i]);            else                 inc = 1;        }        for (int i = n-2,inc = 1; i >=0; --i)  //从右到左        {            if (ratings[i] > ratings[i+1])                candy[i] = max(inc++,candy[i]);            else                inc = 1;        }      return accumulate(&candy[0],&candy[0]+n,n);//每个孩子至少一个    }};int main(){    vector<int> ratings1 = {1,3,5,7,9};    vector<int> ratings2 ={5,4,3,2,1};    vector<int> ratings3 = {1,3,5,2,1};    int sum1=0,sum2=0,sum3=0;    Solution solution;    sum1 = solution.candy(ratings1);    sum2 = solution.candy(ratings2);    sum3 = solution.candy(ratings3);    cout<<"ratings1: "<<sum1<<endl;    cout<<"ratings2: "<<sum2<<endl;    cout<<"ratings3: "<<sum3<<endl;    return 0;}

参考文章：
http://blog.csdn.net/ljiabin/article/details/39061181
http://www.cnblogs.com/felixfang/p/3620086.html