c18b.cpp

《C++程序设计习题及解答》配套代码VC版

// c18b.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <iostream.h>
#include <time.h>

inline int comp1( int a, int b ) 
{ 
	int one;
	one = a;
	one++;
	one += a;
	one--;
	one -= b;

	return (one>b)?one:b; 
}

int comp2( int a, int b ) 
{ 
	int one;
	one = a;
	one++;
	one += a;
	one--;
	one -= b;

	return (one>b)?one:b; 
}

int main(int argc, char* argv[])
{
	double t1, t2;
	t1 = (double) clock();
	for ( int m = 0; m < 10000; m++ )
		for ( int n = 0; n < 10000; n++ )
			comp1(m ,n);
	t2 = (double)clock();
	cout << "调用内联函数运行时间为:\t" << (t2-t1)/CLK_TCK << "秒\n";

	t1 = (double)clock();
	for ( m = 0; m < 10000; m++ )
		for( int n = 0; n < 10000; n++ )
			comp2(m, n);
	t2 = (double)clock();
	cout << "调用外部函数运行时间为:\t" << (t2-t1)/CLK_TCK << "秒\n";

	t1 = (double)clock();
	for ( m = 0; m < 10000; m++ )
		for( int n = 0; n < 10000; n++ )
		{
			int one;
			one = m;
			one++;
			one += m;
			one--;
			one -= n;
			(one>n)?one:n; 
		}
	t2 = (double)clock();
	cout << "直接运行时间为:\t" << (t2-t1)/CLK_TCK << "秒\n";

	return 0;
}