【LeetCode】455. Assign Cookies(分配饼干)


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.

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.



证明:假设在某次选择中,贪心策略选择给第 i 个孩子分配第 m 个饼干,并且第 i 个孩子满足度最小,第 m 个饼干为可以满足第 i 个孩子的最小饼干,利用贪心策略最终可以满足 k 个孩子。假设最优策略在这次选择中给 i 个孩子分配第 n 个饼干,并且这个饼干大于第 m 个饼干。我们发现使用第 m 个饼干去替代第 n 个饼干完全不影响后续的结果,因此不存在比贪心策略更优的策略,即贪心策略就是最优策略。

public int findContentChildren(int[] g, int[] s) {
    int i = 0, j = 0;
    while(i < g.length && j < s.length){
        if(g[i] <= s[j]) i++;
    return i;
Last modification:March 21st, 2018 at 08:35 pm
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