ÈÝÆ÷ÀàÖÐreserve()µÄÓ÷¨¡¢×÷Óã¿

#include <iostream>
#include <vector>
#include <string>
using namespace std;
void print_size(vector<int> &);
int main()
{
vector<int> ivec(4);
cout<<"sizeΪµ±Ç°ÔªËØÊýÁ¿¡¢capacityΪµ±Ç°¿Õ¼ä×ÜÁ¿\n";
print_size(ivec);
ivec.push_back(0);
print_size(ivec);
while(ivec.size()!=ivec.capacity())
ivec.push_back(0);
ivec.push_back(0);
print_size(ivec);
cout<<"¿É¿´³öÿµ±ÈÝÆ÷±ØÐë·ÖÅä¿Õ¼äʱ£¬Ëü¼Ó±¶µ±Ç°ÈÝÁ¿\n";
//²âÊÔreserve\resize
ivec.resize(0);
print_size(ivec);
cout<<"¿É¿´³öresizeÇå¿ÕÁËËùÓÐÔªËØ,¿Õ¼ä×ÜÁ¿Ã»±ä\n";
ivec.reserve(50);
print_size(ivec);
cout<<"¿É¿´³öreserveÉèÖÃÁË¿Õ¼ä×ÜÁ¿\n";
//×°ÂúÈÝÆ÷
while(ivec.size()!=ivec.capacity())
ivec.push_back(0);
print_size(ivec);
cout<<"×°ÂúÈÝÆ÷ºó²¢Ã»ÓÐÖØзÖÅä¿Õ¼ä\nÎÒÃÇÔÙ¼ÓÒ»¸öÔªËØÉÏÈ¥\n";
ivec.push_back(0);
print_size(ivec);
cout<<"Öظ´¸Õ²ÅµÄ¹ý³Ì\n";
while(ivec.size()!=ivec.capacity())
ivec.push_back(0);
ivec.push_back(0);
print_size(ivec);
cout<<"\n\n×îºóreserve²¢²»ÊǶ¨ÒåÁËÒ»ÖÖ·ÖÅä²ßÂÔ"
<<"\n¶øÊǶ¨ÒåÁ˵±Ç°µÄ¿Õ¼ä×ÜÁ¿" <<endl;
return 0;
}
void print_size(vector<int> &ivec)
{
cout<<"size: " <<ivec.size()
<<" capacity: " <<ivec.capacity()
<<endl;
}