LeetCode--455. Assign Cookies

455. Assign Cookies

Description：

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.

Solution：

将两组数组由小到大排序，分配两个指针，都从最小端开始，如果满足条件，二者同时右移；不满足的话，size的指针右移，size增大，再比较是否满足条件。

Code：

class Solution {
public:
int findContentChildren(vector<int>& g, vector<int>& s) {
sort(g.begin(),g.end());
sort(s.begin(),s.end());

int i = 0;//greedy指针
int j = 0;//size指针

while (i<g.size() && j<s.size()) {
if (g[i]<=s[j]) {//可以满足孩子的greedy期望值
i++;
j++;
} else {//不可满足，指针右移，size增大
j++;
}
}

return i;
}
};

Test：


Your input

[1,8,4,2]
[1,1,3,5]

Your answer

3

Expected answer

3