【leetcode】Candy

原题：http://oj.leetcode.com/problems/candy/

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?

代码：

class Solution {public:    int candy(vector<int> &ratings) {        // Note: The Solution object is instantiated only once and is reused by each test case.                if(ratings.size() == 1){            return 1;        }        if(ratings.size() < 1){            return 0;        }        vector<int> result(ratings.size(),1);        vector<int> res(ratings.size(),0);        while(res != result){            res = result;            if(ratings[0]>ratings[1] && result[0]<=result[1]){                result[0] = result[1] + 1;            }            for(vector<int>::size_type i=1 ; i<result.size()-1 ; i++){                if(ratings[i]>ratings[i-1] && result[i]<=result[i-1]){                    result[i] = result[i-1] + 1;                }                if(ratings[i]>ratings[i+1]  && result[i]<=result[i+1]){                    result[i] = result[i+1] + 1;                }            }            if(ratings[ratings.size()-1]>ratings[ratings.size()-2] && result[result.size()-1]<=result[result.size()-2]){                result[result.size()-1] = result[result.size()-2] + 1;            }        }        int ret = 0;        for(vector<int>::size_type i=0 ; i<result.size() ; i++){   //         cout<<result[i] <<"\t";            ret = ret + result[i];        }        return ret;    }};

总结：先给每人一颗，然后逐次遍历，直到满足要求。