相信会来看这篇博客的人,应该都认识vector了,所以我就直接上测试代码了,我是在vs2015中测试的:
#include<iostream>
#include<vector>
#include<windows.h>
using namespace std;
int main() {
//建立4个vector,使用列表初始化,相当与调用拷贝构造函数
vector<int> v1;
int temp;
int i;
for (i = 0; i < 100000; ++i) {
v1.push_back(i);
}
//测试1
DWORD start,end;
start= GetTickCount();
for (i = 0; i < v1.size(); ++i) {
temp=v1[i];
}
end = GetTickCount();
cout << "使用[]运算符耗时:" << end - start << "ms" << endl;
//测试2
start = GetTickCount();
for (auto k = v1.begin(); k < v1.end(); ++k)
{
temp = *k;
}
end = GetTickCount();
cout << "使用迭代器(++k)耗时:" << end - start << "ms" << endl;
//测试3
start = GetTickCount();
for (auto k = v1.begin(); k < v1.end(); k++)
{
temp = *k;
}
end = GetTickCount();
cout << "使用迭代器,使用k++,而不是++k:" << end - start << "ms" << endl;
//测试4
start = GetTickCount();
i = 0;
for (auto k = v1.begin(); i<v1.size(); ++i,++k)
{
temp = *k;
}
end = GetTickCount();
cout << "使用迭代器,不使用end()方法:" << end - start << "ms" << endl;
system("pause");
return 0;
}
输出: