写一个程序，让控制cpu利用率在20%左右
思路很简单：每个循环控制sleep的时间占比

#include <iostream>
#include <chrono>
#include <unistd.h>int main() {int ratio = 20;int base_time = 1000;int sleeptime = base_time * (100-ratio);int runtime = base_time * ratio;while(true) {auto start = std::chrono::high_resolution_clock::now();while(std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now() - start).count() < runtime) {}usleep(sleeptime);}return 0;
}