写一个程序,让用户来决定任务管理器(Task Manager)的CPU占用率,程序越精简越好,编程语言不限。
#include<iostream>
#include<Windows.h>
using namespace std;
int main()
{
for (;;)
{
for (int i = 0; i < 960000; i++)
;
Sleep(10);
}
return 0;
}
以上程序对于不同的CPU,很难确定n取值。对于某一台指定的计算机,可能CPU的占用率刚好为50%。实际情况中不同电脑CPU不同,并且不同电脑上运行的程序也不同,如何保持50%的CPU占用率?
下面是大牛的程序:
#include<iostream>
#include<Windows.h>
#include<stdlib.h>
#include<math.h>
const double SPLIT = 0.01;
const int COUNT = 200;
const double PI = 3.14159265;
const int INTERVAL = 300;
using namespace std;
int main()
{
DWORD busySpan[COUNT];
DWORD idleSpan[COUNT];
int half = INTERVAL / 2;
double radian = 0.0;
for (int i = 0; i < COUNT; i++)
{
busySpan[i] = (DWORD)(half + (sin(PI * radian)*half));
idleSpan[i] = INTERVAL - busySpan[i];
radian += SPLIT;
}
DWORD startTime = 0;
int j = 0;
while (true)
{
j = j % COUNT;
startTime = GetTickCount();//caculate the time since the system started
while ((GetTickCount() - startTime) <= busySpan[j])
;
Sleep(idleSpan[j]);
j++;
}
return 0;
}