Question

I have data in a particular format and I want to store them through vectors/pairs/maps in c++.
eg:

Group A          Group B   Group C  ........
John             Matt      Shawn            
Jane             Liam      Tom              
.
.
.

There can be any number of groups and any number of names in them (all strings).
I expect as groups to be formed (which can be any in number) with any number of names in them. So I tried declaring them as a map or a pair.
The above format is what I want to store.
I tried doing it in this form:

Map<vector<int>, vector<string> > groups;
groups[i] = names.at(i);

Doesnt work.

The code of the method is:-

void form_groups(vector<string> teams){
          pair<vector<int>, vector<string> > groups;
          int num_teams_in_grp = 0;
          int group_num = 1;
          int i = 0;
          while( i < teams.size())
                  {
                          groups[group_num] = teams.at(i++);
                          num_teams_in_grp++; 
                  }       
                  group_num++;
         }

Answer 1

You have been vague with your format so I’ll make the following assumption. You have some number of group names, and some number of groups, each group being defined as a set of members.

I recommend storing them like this:

#include <map>
#include <set>

...

// members of groups stored in sets, keyed by group name
map<string, set<string> > groups; 

...

// to access groups:
set<string>& somegroup      = groups["Minions"];
set<string>& someothergroup = groups["Judicators"];

To add people to a group, using your specific data format, which I assume to be:

Group1 Group2 Group3 ... GroupN
Member1_Group1 Member2_Group1 Member3_Group1 ... MemberM_Group1
...
Member1_GroupN Member2_GroupN Member3_GroupN ... MemberM_GroupN

You would have to keep track of the indices of each group name so you could keep track of which group you were supposed to be adding members to, by line. For that purpose you might use something like the following C++ like pseudocode:

vector<string> groups_by_index;            // stores group names by index numbers
int current_line = 0;                      // stores the index of the group to add to

for each item on line:                     // store group names by index
    groups_by_index.push_back(item);

for each remaining line:                   // loop over each groups members
    for each item on line:
        groups[current_line].insert(item); // add member to group
    ++current_line;                        // increment group index