c++ finding same record in vector

Question

Ihave a vector that contains monthyear Jan2013 Jan2013 Jan2013 Jan2014 Jan2014 Jan2014 Jan2014 Feb2014 Feb2014 Basically what I want to do is to search through the vector, for every same record, group them together like e.g ``` total count for Jan2013 = 3; total count for Jan2014 = 4; total count for Feb2014 = 2; ``` Of course as we know, we can just simply write multiple if to solve it ``` if(monthyear = "Jan2013") { //add count } if(monthyear = "Jan2014") { //add count } if(monthyear = "Feb2014") { //add count } ``` but no way a programmer is going code it in this way. what if there's additional monthyear march2014,april2014,may2014 all the way to dec2014 and jan2015-dec2015 and so on. I don't think I should be adopting this kind of hard-coding method in the long run and looking for a more dynamic approach. I not asking for codes, but just some steps and perhaps give me some hints on what c++ methods should I be researching on. Thanks in advance

Accepted Answer

You can use `std::map`. For example

```
std::map<std::string, size_t> m;

for ( const std::string &s : v ) ++m[s];
```

c++ finding same record in vector

Solution

Problem