C++/C get system time, get program execution time

Personally think the second kind is more practical, but also the most commonly used ~

However, when the calculation algorithm time-consuming, do not forget second, not as long as the milliseconds to reduce, otherwise negative, if the algorithm time is too long to use minutes. Otherwise, hours ...

Scenario-Advantages: Use only C standard library; Disadvantage: only accurate to second level

#include <time.h>
#include <stdio.h>
int main (void)
{
time_t t = time (0);
Char tmp[64];
Strftime (TMP, sizeof (TMP), "%y/%m/%d%x%A year%j days%z", LocalTime (&t));
Puts (TMP);
return 0;
}
size_t strftime (char *strdest, size_t maxsize, const char *format, const struct TM *timeptr);
Generates a string based on a format string.
struct TM *localtime (const time_t *timer);
Get local time, LocalTime gets the results returned by the Fabric TM
The returned string can be in the following format:
%a abbreviation of the week. Eg:tue
%A the full name of the week. Eg:tuesday
The abbreviation for the%b month name.
The full name of the%B month name.
The%c local end datetime is a better representation of the string.
%d numbers indicate the day ordinal of the month (range 00 to 31). Date
The%H uses a 24-hour number to denote the number of hours (ranging from 00 to 23).
%I A 12-hour number indicates the number of hours (range 01 to 12).
%j indicates the day of the Year in Numbers (range 001 to 366).
Number of%m months (range from 1 to 12).
%M minutes.
%p indicates local time with ' AM ' or ' PM '.
%s Number of seconds.
The number of%u is expressed as the week of the current year, and the first one weeks start in Sunday.
The%W number is expressed as the week of the current year, and the first one weeks start in Monday.
%w numbers indicate the day of the week (0 is Sunday).
%x does not include date notation for time.
%x does not include a time representation of the date. Eg:15:26:30
The%y two digits represent the year (range from 00 to 99).
%Y a full year number representation, that is, four digits. eg:2008
%Z (%Z) time zone or name abbreviation. EG: China Standard Time
Percent% character.

Scenario Two advantages: can be accurate to the millisecond level; Cons: Using the Windows API
#include <windows.h>
#include <stdio.h>
int main (void)
{
SYSTEMTIME SYS;
Getlocaltime (&sys);
printf ("%4d/%02d/%02d%02d:%02d:%02d.%0 3d Week%1d\n ", Sys.wyear,sys.wmonth,sys.wday,sys.whour,sys.wminute, Sys.wsecond,sys.wmilliseconds,sys.wdayofweek);
return 0;
}
Scenario three, advantages: using System functions, can also modify the system time
This file must be a C + + file
#include <stdlib.h>
#include <iostream>
using namespace Std;
void Main ()
{
System ("Time");
}
Scenario four, convert the current time to a second level, and then the corresponding time conversion can be
This file must be a C + + file
#include <iostream>
#include <ctime>
using namespace Std;
int main ()
{
time_t Now_time;
Now_time = time (NULL);
cout<<now_time;
return 0;
}

C++/C get system time, get program execution time