Data structure which supports table lookups

You might want to make a std::map with the first 4 columns as key, and the 5th as value. I've taken columns to be of mixed std::string and int type, but you could generalize that to whatever you like.

#include <map> #include <utility> #include <tuple> #include <iostream> #include <string> typedef std::map< std::tuple<std::string, std::string, int, int>, int> Table; int main() { Table my_table; std::string a = "Kode", b = "Warrior"; int c = 3, d = 4, e = 5; // 1. Support insert operations for each row. my_table.insert(std::make_pair(std::make_tuple(a, b, c, d), e)); // 2. Given the values for Col1, Col2, Col3, Col4 find the value of Col5 auto it = my_table.find(std::make_tuple(a, b, c, d)); std::cout << it->second; // prints e // 3. Given Col1, Col2, COl3, Col4 update Col5 it->second = 6; // assign some other value } 

Output on Ideone.

One big drawback (but it wasn't in your requirements): it does not support column insertion, so it's not a good model for a spreadsheet. You could try to use a std::map< std::vector<std::string>, std::string> for that as mentioned by @NarutSereewattanawoot in the comments. You can modify your code to support that but you need some initializer-list mechanics to get a make_vector to have compact lookup syntax. OTOH, the drawback of a std::vector as a key is that you need type homogeneity which std::tuple avoids. If you want to get really fancy pancy, you could have a std::vector<boost::any> as the key which is both type-flexible and column-size flexible.