12. leetcode 455.Assign Cookies

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 g_i, which is the minimum size of a cookie that the child will be content with; and each cookie j has a size s_j. If s_j >= g_i, 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.

思路：由于一个孩子只能给一个，所以先把两个数组分别排序，然后逐个比对。