[leetcode]解决Assign Cookies的一点小心得

本次选择的题目是

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.

Solution：

一开始想把每一步的步骤都表示出来：
主要采取的策略是：最小的size匹配最小的需求。如果匹配不了，找次小的size匹配最小的需求，以此类推。

#include <iostream>  #include <vector> using namespace std;  struct Child{    int index;    int greed;    bool mark;};struct Cookie{    int index;    int size;    bool mark;};class Solution {public:    int findContentChildren(vector<int>& g, vector<int>& s) {        if(g.size()==0||s.size()==0)        {            return 0;        }        Child child[g.size()];        Cookie cookie[s.size()];        int max_s = 0;        int max_g = 0;        for (int i = 0;i < s.size();i++)        {            if(s[i]>max_s){                max_s = s[i];            }        }        for (int i = 0;i < g.size();i++)        {            if(g[i]>max_g){                max_g = g[i];            }        }        int min_s = max_s;        int min_g = max_g;        int index_s;        int index_g;        int trytime = 0;        int assigned = 0;        for (int i = 0;i < g.size();i++)        {            child[i].index = i + 1;            child[i].greed = g[i];            child[i].mark = false;        }        for (int i = 0;i < s.size();i++)        {            cookie[i].index = i + 1;            cookie[i].size = s[i];            cookie[i].mark = false;        }        while(trytime != s.size())        {            min_s = max_s;            min_g = max_g;            for (int i = 0;i < s.size();i++)            {                if(cookie[i].mark == false && cookie[i].size <= min_s)                {                    index_s = i;                    min_s = cookie[i].size;                }            }            cookie[index_s].mark = true;            trytime++;            for (int i = 0;i < g.size();i++)            {                if(child[i].mark == false && child[i].greed <= min_g)                {                    index_g = i;                    min_g = child[i].greed;                }            }            if(min_s >= min_g&&child[index_g].mark != true)            {                child[index_g].mark = true;                assigned++;            }        }        return assigned;    }};

只计算匹配成功的次数：

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,count = 0;        while(i<g.size() && j<s.size())        {            if(g[i]>s[j]) j++;            else if(g[i++]<=s[j++]) count++;        }        return count;    }};