LeetCode: 455 Assign Cookies(easy)

题目：

Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie. Each child i has a greed factor gi, which is the minimum size of a cookie that the child will be content with; and each cookie j has a size sj. If sj >= gi, we can assign the cookie j to the child i, and the child i will be content. Your goal is to maximize the number of your content children and output the maximum number.

Note:
You may assume the greed factor is always positive. 
You cannot assign more than one cookie to one child.

Example 1:

Input: [1,2,3], [1,1]

Output: 1

Explanation: You have 3 children and 2 cookies. The greed factors of 3 children are 1, 2, 3. 
And even though you have 2 cookies, since their size is both 1, you could only make the child whose greed factor is 1 content.
You need to output 1.

Example 2:

Input: [1,2], [1,2,3]

Output: 2

Explanation: You have 2 children and 3 cookies. The greed factors of 2 children are 1, 2. 
You have 3 cookies and their sizes are big enough to gratify all of the children, 
You need to output 2.

代码：

class Solution {
public:
    int findContentChildren(vector<int>& g, vector<int>& s) {
        int result = 0;
        while ((!g.empty())&&(!s.empty())){
            auto gmax = max_element(g.begin(), g.end());
            auto smax = max_element(s.begin(), s.end());
            if (*gmax <= *smax){
                result++;
                g.erase(gmax);
                s.erase(smax);
            }
            else
                g.erase(gmax);
        }
        return result;
    }
};

改良版：

class Solution {
public:
    int findContentChildren(vector<int>& g, vector<int>& s) {
        int result = 0;
        sort(g.begin(), g.end(), greater<int>());
        sort(s.begin(), s.end(), greater<int>());
        vector<int>::iterator gtem = g.begin();
        vector<int>::iterator stem = s.begin();
        
        while (gtem != g.end() && stem != s.end()){
            if (*gtem > *stem)
                gtem++;
            else{
                result++;
                gtem++;
                stem++;
            }
        }
        return result;
    }
};