DP(3)

LeetCode #135

int candy(vector<int> &ratings) {    int len = ratings.size();    vector<int> candy_vec(len);    //初始化    for (auto &i : candy_vec)        i = 1;    //left -> right    for (int i = 1; i < len; i++)    {        if (ratings[i] > ratings[i - 1] && candy_vec[i] <= candy_vec[i - 1])            candy_vec[i] = candy_vec[i - 1] + 1;    }    //right -> left    for (int i = len - 2; i >= 0; i--)    {        if (ratings[i] > ratings[i + 1]&&candy_vec[i]<=candy_vec[i+1])            candy_vec[i] = candy_vec[i + 1] + 1;    }    int sum = 0;    for (auto i : candy_vec)        sum += i;    return sum;}