#include <iostream>  //as usual basic i/o objects
#include <chrono> //for C++11 time like the seconds() line 32
#include <ctime>  //C time functions--useful
#include <thread>  //for the sleep function line 32

using namespace std;
using namespace std::chrono;  //the C++11 time library namespace

int main() {
	time_t st=time(nullptr);  //set programme startup time
	tm* startTime{localtime(&st)};  //setup a tm structure(for time information based on st(ie: startup time))
	tm timeObj;
	unsigned hr=0,min=0;

	cout<<"Enter prescribed hour(24hr clock): ";
	cin>>hr;  //user enters hour 0 - 23
	cout<<"\nEnter prescribed minute: ";
	cin>>min;  //user enters minute 0 - 60

	if((hr>=0)&&(hr<=23)&&(min>=0)&&(min<=60)) {  //check
		timeObj=*startTime; //assign timeObj the startup time
		timeObj.tm_hour=hr; //set the hour aspect of the startup time to the user defined one
		timeObj.tm_min=min; //set the minute aspect of the startup time to the user defined one

		//time difference in seconds between user defined time and startup time
		double timeDiff=difftime(mktime(&timeObj),st);

		if(timeDiff<0.0) {
			cout<<"Time passed!!!"; //tell the user to be careful
		}
		else {
			this_thread::sleep_for(seconds((int)timeDiff)); //wait for truncated-to-int "time difference" seconds
									//this ensures(not effectively) the user is informed on the time
									//the drug must be taken
			cout<<"\a\a\a\a\a\n\nHey!!! Take your drugs NOW!!!\a\a\a\a\a";  //inform
		}
	}
	delete startTime;  //clear stuff

	return 0;