[leetcode]455. Assign Cookies

greedy

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: 1Explanation: 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: 2Explanation: 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：

贪心：要想发饼干给尽可能多的小朋友，就要发给尽可能接近他们胃口的大小的饼干。分别对两个vector升序排序，然后遍历两个vector，如果s[i]>=g[j]，则i++,j++；否则i++,将s[i+1]与g[j]进行比较。当遍历完s[]后，当前j的值就是已经满足的孩子的个数。

class Solution {public:    int findContentChildren(vector<int>& g, vector<int>& s) {        sort(g.begin(), g.end());        sort(s.begin(), s.end());        int i = 0, j = 0;        while (i < s.size() && j < g.size()) {            if (s[i] >= g[j]) {                i++;                j++;            } else if (s[i] < g[j]) {                i++;            }        }        return j;    }};