How to simplify many if else statements

Question

I want to simplify this code and want to make it smarter, there are about 80 singleS and multipleS's. I considered State design pattern usage but it seems that it wont be simpler. Can anybody help me with the below lines:

void spy::run(string num, SingleS single, MultipleS multipleS)
{
if(num == "1")
{singleS.runS1}
else if(num == "2")
{singleS.runS2}
else if(num == "3")
{singleS.runS3}
else if(num == "4")
{singleS.runS4}
else if(num == "5")
{singleS.runS5}
else if(num == "6")
{singleS.runS6}
else if(num == "7")
{singleS.runS7}
else if(num == "8")
{singleS.runS8}
else if(num == "9")
{singleS.runS9}
else if(num == "10")
{multipleS.runS10}
else if(num == "11")
{multipleS.runS11}
else if(num == "12")
{multipleS.runS12}
else if(num == "13")
{multipleS.runS13}
}
}

Answer 1

You can use std::map or std::unordered_map like that

std::unordered_map<std::string, std::function<void(void)>> functionsMap = {
   {"1", std::bind(&SingleS::runS1, &singleS)},
   {"12", std::bind(&MultipleS::runS12, &multipleS)},
...
};

auto it = functionsMap.find(num);
if (it != functionsMap.end())
    it->second();
...

Links: http://www.cplusplus.com/reference/functional/bind/ , http://www.cplusplus.com/reference/functional/function/function/ ,http://www.cplusplus.com/reference/unordered_map/unordered_map/

Answer 2

You can try nested ternary:

void spy::run(string num, SingleS single, MultipleS multipleS)
{

    (num=="1")?singleS.runS1:(num=="2")?singleS.runS2:(num=="3")?singleS.runS3:(num=="4")...;
}