Question

I am using C++ and i have 2 vectors that a related to each other:

vector<double> val = {.3,.5,.2,.4};
vector<string> str = {'a','b','c','d'};

I would like to search val for the max, and then return the string from str in the same position:

vector<double>::const_iterator it;
it = max_element(val.begin(), val.end());

So, how can i use it inside str to get the letter?

string lettter;
letter = str.at(it-> ????? );

Thank!!!

Answer 1

You can find out how far it is from the beginning of val and then use that to index str:

str[std::distance(std::begin(val), it)]

By using std::distance, this will still work if you change the type of val to a container whose iterator does not provide random access. However, when using it on a random access iterator, you will still get constant time complexity. Using std::begin allows you to change val to an C-style array if you ever wanted to.

It’s worth mentioning that you should be initialising str with:

vector<string> str = {"a","b","c","d"};

std::string has no constructor that takes a char.