#include <iostream>
#include <ctime>
using namespace std;
/////////////////
void dosum(int n)
{
	int sum1;
	for(int i=1;i<n;i++)
	{
		sum1 += n;
	}
	cout<<"sum1 = "<<sum1<<endl;
}
///////////////
int main(int argc, char** argv) {
	//計算運算執行時間
	double startTime,endTime; 
	startTime = clock();
	
	//call function 
    	dosum(990000);
    
 	endTime = clock();
 	cout<<"\n運算所需時間 = "<<(endTime-startTime)<<" ms"<<endl;
 
    	cout<<endl;
    
	return 0;
}