C++ Array vs vector
- by blue_river
when using C++ vector, time spent is 718 milliseconds,
while when I use Array, time is almost 0 milliseconds.
Why so much performance difference?
int _tmain(int argc, _TCHAR* argv[])
{
const int size = 10000;
clock_t start, end;
start = clock();
vector<int> v(size*size);
for(int i = 0; i < size; i++)
{
for(int j = 0; j < size; j++)
{
v[i*size+j] = 1;
}
}
end = clock();
cout<< (end - start)
<<" milliseconds."<<endl; // 718 milliseconds
int f = 0;
start = clock();
int arr[size*size];
for(int i = 0; i < size; i++)
{
for(int j = 0; j < size; j++)
{
arr[i*size+j] = 1;
}
}
end = clock();
cout<< ( end - start)
<<" milliseconds."<<endl; // 0 milliseconds
return 0;
}
