C++ STL map update all of the values at the same time - c++

Question

I need to update all the values (integers) of a map in C++. All the values are going to be multiplied by a float (0.30), so no need to do it one by one.
I can do it manually but I want to know if there is a way to multiply them all at once.
map < string, int >ouremployees = {
{"Haaziq", 80000},
{"Aldo", 100000},
{"Monte", 30000},
{"Carlo", 20000},
{"Afif", 50000},
// THERE ARE MORE WAY WAY MORE BUT ALL THE INT NUMBERS/ VALUES NEED TO BE //MULTIPLIED BY .30 ALL OF THEM
};

Answer 1

In any case you have to do this "manually".:)
Here is a demonstrative program
#include <iostream>
#include <map>
int main()
{
std::map <std::string, int> ouremployees =
{
{ "Haaziq", 80000 },
{ "Aldo", 100000 },
{ "Monte", 30000 },
{ "Carlo", 20000 },
{ "Afif", 50000 },
};
double multiplier = 0.3;
for ( auto &p : ouremployees ) p.second *= multiplier;
for ( const auto &p : ouremployees ) std::cout << p.first << ' ' << p.second << '\n';
return 0;
}
Its output is
Afif 15000
Aldo 30000
Carlo 6000
Haaziq 24000
Monte 9000
Instead of the range-based for loop you could for example use standard algorithm std::for_each.
Fro example
#include <iostream>
#include <map>
#include <iterator>
#include <algorithm>
int main()
{
std::map <std::string, int> ouremployees =
{
{ "Haaziq", 80000 },
{ "Aldo", 100000 },
{ "Monte", 30000 },
{ "Carlo", 20000 },
{ "Afif", 50000 },
};
std::for_each( std::begin( ouremployees ), std::end( ouremployees ),
[multiplier = 0.3]( auto &p ) { p.second *= multiplier; } );
for ( const auto &p : ouremployees ) std::cout << p.first << ' ' << p.second << '\n';
return 0;
}
Pay attention to that maybe the second template argument of the map should be declared as the type argument double.

Answer 2

Thanks a lot indeed!
In the end I ended up doing it like this:
int salary_it; // this var will hold salaries
string name_it;// THIS VARIABLE WILL HOLD THE KEY , EITHER FOOD NAME OR EMPLOYEE NAME
//we change all salaries
map < string, int >::iterator it3b;
for (it3b = ouremployees.begin (); it3b != ouremployees.end (); it3b++)
{
salary_it=it3b->second;
name_it=it3b->first;
cout<<name_it<<" "<<salary_it<<endl;
//NOW WE CAN EITHER USE A find, or [], since the key is being retrived from the
//map itself then there is no risk in using the []
ouremployees[name_it]=salary_it+=salary_it*.30;//instead of .30 we can ask for percentage
}