LeetCode 455. Assign Cookies

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.

解析

题目中要求更多的分配cookies，即“贪心”。实现的思路比较简单，根据题目中的逻辑进行实现即可，即从左至右遍历s，如果比g大，即满足该child。

实现（C语言）

int comp(const void* a, const void* b) {
    return *(int*)a > *(int*)b;
}

int findContentChildren(int* g, int gSize, int* s, int sSize) {
    qsort(g, gSize, sizeof(int), comp);
    qsort(s, sSize, sizeof(int), comp);
    
    int count = 0, j = 0;
    
    for (int i = 0; i < sSize; ++i) {
        if (s[i] >= g[j]) {
            ++count;
            ++j;
            
            if (j >= gSize)
                break;
        }
    }
    
    return count;
}

实现中使用到了qsort库函数，即将数组进行从大到小排序，先从大到小进行满足，可以更多的满足child，这个是显然的。