8.16

https://leetcode.com/problems/missing-number/description/
https://leetcode.com/problems/roman-to-integer/description/?envType=problem-list-v2&envId=hash-table
https://leetcode.com/problems/missing-number/solutions/1637159/python-solution-using-bloom-filters-cheeky-but-ultimately-a-good-learning-exercise/

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        vector<bool> isNumberExist(nums.size());
        int result;
        for(auto i:nums){
            isNumberExist[i] = true;
        }
        for(int j=0;j<isNumberExist.size();j++){
            if(isNumberExist[j]==false){
                result = j;
                break;
            }
        }
        return result;
    }
};

class Solution {
public:
    int romanToInt(string s) {
        unordered_map<string, int> symbolTable;
        symbolTable["I"] = 1;
        symbolTable["II"] = 2;
        symbolTable["IV"] = 4;
        symbolTable["IX"] = 9;

        symbolTable["V"] = 5;

        symbolTable["X"] = 10;
        symbolTable["XX"] = 20;
        symbolTable["XL"] = 40;
        symbolTable["XC"] = 90;

        symbolTable["L"] = 50;

        symbolTable["C"] = 100;
        symbolTable["CC"] = 200;
        symbolTable["CD"] = 400;
        symbolTable["CM"] = 900;

        symbolTable["D"] = 500;
        symbolTable["M"] = 1000;
        symbolTable["MM"] = 2000;

        int sum = 0;
        for(int i=0;i<s.size();){
            if(s.size() > i+1){
                string explore;
                explore = s.substr(i,1) + s.substr(i+1,1);

                // 2개씩 탐색했을 때 쌍이 있는 경우
                auto item = symbolTable.find(explore);
                if(item != symbolTable.end()){
                    sum += symbolTable[explore];
                }else{ // 2개씩 탐색했는데 쌍이 없는 경우 하나만 탐색하고 나가기
                    sum += symbolTable[s.substr(i,1)];

                    std::cout << explore << std::endl;
                    std::cout << sum << std::endl;

                    i+=1;
                    continue;
                }

                std::cout << explore << std::endl;
                std::cout << sum << std::endl;

                i += 2;
            }else{
                sum += symbolTable[s.substr(i,1)];
                i+=1;
            }
        }
        return sum;
    }
};