The other day, I was writing some code to familiarize myself with vectors and maps. Here it goes -
#include <iostream>
#include <map>
#include <vector>
using std::string;
using std::cout;
using std::endl;
using std::vector;
//Todo: check how to use overloading for 'print' function
void print(std::map<string,int> &m) {
std::map<string,int>::const_iterator it;
for(it=m.begin();it!=m.end();++it) {
std::cout << (it)->first << " = " << (it)->second << std::endl;
}
}
//Todo: check how to use overloading for 'print' function
void print(vector<int> v) {
vector<int>::const_iterator it;
for(it=v.begin();it!=v.end();++it) {
std::cout<< (*it) << std::endl;
}
}
void initializevec(vector<int> &vec) {
for (unsigned int i = 0 ; i < 20; ++i) {
vec.push_back(i);
//demonstrates how capacity grows as size of vector increases
cout << "size = " << vec.size() << " capacity = " << vec.capacity() << endl;
}
}
int main() {
cout<< " MAP " << endl;
std::map<string,int> mymap;
mymap["b"] = 1;
mymap["a"] = 2;
mymap["c"] = 5;
mymap["d"] = 3;
print(mymap);
cout << "size = " << mymap.size() << endl;
std::map<string,int>::iterator it = mymap.find("c");
cout<< "Deleting 'c' ... " <
mymap.erase(it);
print(mymap);
cout << "size = " << mymap.size() << endl;
std::cout << std::endl;
cout<< " VECTOR " << endl;
vector<int> vec;
initializevec(vec);
vec.push_back(13);
print(vec);
return 0;
}
Compile using -
g++ -W -Wall -Weffc++ -ggdb -O0 filename.cpp
It demonstrates some basic operations of maps and vectors. It was nice to understand how vectors increase their 'capacity' to accommodate new elements.
