STL-vector中reserve和resize的區…

#include"iostream"

#include"vector"

#include"cstdlib"

using namespace std;

int main()

{

vectorivec;

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

ivec.push_back(1);

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

ivec.push_back(2);

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

ivec.push_back(3);

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

ivec.push_back(4);

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

ivec.reserve(100);

cout<<ivec.size()<<' '<<ivec.capacity()<<endl;

for(int i=0;i<104;i++)

cout<<ivec[i]<<' ';

cout<<endl;

cout<<".............................."<<endl;

vectorvect;

vect.push_back(1);

    vect.push_back(2);

    vect.push_back(3);

    vect.push_back(4);

    cout<<vect.size()<<' '<<vect.capacity()<<endl;

    vect.resize(2);

    cout<<vect.size()<<' '<<vect.capacity()<<endl;

    for(int i=0;i<20;i++)

cout<<vect[i]<<' ';

cout<<endl;

vect.resize(100);

cout<<vect.size()<<' '<<vect.capacity()<<endl;

system("pause");

return 0;

}