Today I have done leetcode's January LeetCoding Challenge with cpp.

January LeetCoding Challenge 1

Description

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.

Example 1:

Input: g = [1,2,3], s = [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: g = [1,2], s = [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.

Constraints:

• 1 <= g.length <= 3 * 104
• 0 <= s.length <= 3 * 104
• 1 <= g[i], s[j] <= 231 - 1

Solution

class Solution {
public:
  int findContentChildren(vector<int>& g, vector<int>& s) {
    sort(g.begin(), g.end());
    sort(s.begin(), s.end());
    int posG = g.size() - 1;
    int posS = s.size() - 1;
    int answer = 0;
    while(posG >= 0 && posS >= 0) {
      while(posG >= 0 && s[posS] < g[posG]) posG -= 1;
      if(posG < 0) break;
      answer += 1;
      posS -= 1;
      posG -= 1; 
    }
    return answer;
  }
};

// Accepted
// 21/21 cases passed (18 ms)
// Your runtime beats 96.56 % of cpp submissions
// Your memory usage beats 6.24 % of cpp submissions (18 MB)