计算时间差 time_t mktime

#include <iostream>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
using namespace std;
time_t convert(int year,int month,int day,int hour,int minute,int second)
{
tm info={0};
info.tm_hour=hour;
info.tm_sec=second;
info.tm_min=minute;
info.tm_year=year-1900;
info.tm_mon=month-1;
info.tm_mday=day;
time_t t=mktime(&info);
return t;
}
int main()
{
time_t end=convert(2017,11,12,10,9,0);
time_t start=convert(2016,11,12,0 ,0 ,0);
int diff=end-start;
cout<<diff/(24*3600)<<endl;
return 0;
}