C++求两个时间的时间差

//---------------------------------------------------------------------------
#pragma hdrstop
//---------------------------------------------------------------------------
#pragma argsused
#include<string>
#include<iostream>
using namespace std;
struct TTime
{
int m_year;
int m_month;
int m_day;
int m_time;
int m_minite;
int m_second;
int m_millsecond;
TTime()
{
m_year = 0;
m_month = 0;
m_day = 0;
m_time = 0;
m_minite = 0;
m_second = 0;
m_millsecond = 0;
}
};
int idayTime[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
double GetSecondTime(const TTime &tSrcTime)
{
double dDayTime = 0;
for(int iIndex = 1; iIndex < tSrcTime.m_month; iIndex ++)
{
dDayTime = dDayTime + idayTime[iIndex -1];
//闰年多一天
if( ((0 == iIndex % 4)&&(0 != iIndex % 100 ))||( 0 == iIndex % 400 ))
{
dDayTime = dDayTime + 1;
}
}
//转换到秒
dDayTime = (dDayTime +  tSrcTime.m_day) * 24 * 3600;
dDayTime = dDayTime + tSrcTime.m_time* 3600 +  tSrcTime.m_minite * 60 + tSrcTime.m_second +  tSrcTime.m_millsecond / 1000;
return dDayTime;
}
void DiffTime(const TTime &tSrcTime,double &dDiffTime)
{
double dYearDiff = tSrcTime.m_year - 2000;
double dyearTime = 0;
double dBetweenTime = 0;
//2000年以后
if(dYearDiff > 0)
{
for(int iIndex = 2000; iIndex < tSrcTime.m_year; iIndex ++)
{
if((0 == iIndex % 4 && 0 != iIndex % 400) || 0 == iIndex % 400)
{
dyearTime = dyearTime + 366;
}
else
{
dyearTime = dyearTime + 365;
}
}
//转换成秒
dyearTime = dyearTime * 24 * 3600;
dBetweenTime = GetSecondTime(tSrcTime);
dDiffTime =  dyearTime +  dBetweenTime;
}
else
{
//2000年之前
for(int iIndex = tSrcTime.m_year; iIndex < 2000; iIndex ++)
{
if((0 == iIndex % 4 && 0 != iIndex % 400) || 0 == iIndex % 400)
{
dyearTime = dyearTime + 366;
}
else
{
dyearTime = dyearTime + 365;
}
//转换成秒
dyearTime = dyearTime * 24 * 3600;
dBetweenTime = GetSecondTime(tSrcTime);
dDiffTime =  dyearTime -  dBetweenTime;
}
}
}
int GetDiffTime(string &srcCompare,string &stcCompareTwo,double &iItem,double &dDiff)
{
TTime m_firstTime;
TTime m_secondTime;
m_firstTime.m_year = atoi(srcCompare.substr(0,4).c_str());
m_firstTime.m_month = atoi(srcCompare.substr(4,2).c_str());
m_firstTime.m_day = atoi(srcCompare.substr(6,2).c_str());
m_firstTime.m_time = atoi(srcCompare.substr(8,2).c_str());
m_firstTime.m_minite = atoi(srcCompare.substr(10,2).c_str());
m_firstTime.m_second = atoi(srcCompare.substr(12,2).c_str());
m_firstTime.m_millsecond = atoi(srcCompare.substr(14,2).c_str());
double dDiffFirstTime;
DiffTime(m_firstTime,dDiffFirstTime);
m_secondTime.m_year = atoi(stcCompareTwo.substr(0,4).c_str());
m_secondTime.m_month = atoi(stcCompareTwo.substr(4,2).c_str());
m_secondTime.m_day = atoi(stcCompareTwo.substr(6,2).c_str());
m_secondTime.m_time = atoi(stcCompareTwo.substr(8,2).c_str());
m_secondTime.m_minite = atoi(stcCompareTwo.substr(10,2).c_str());
m_secondTime.m_second = atoi(stcCompareTwo.substr(12,2).c_str());
m_secondTime.m_millsecond = atoi(stcCompareTwo.substr(14,2).c_str());
double dDiffSecondTime;
DiffTime(m_secondTime,dDiffSecondTime);
double dTimeValue = abs(dDiffFirstTime - dDiffSecondTime);
dDiff = dTimeValue / iItem;
if(strcmp(srcCompare.c_str(),stcCompareTwo.c_str()) < 0 )
{
dDiff = - dDiff;
}
}
int main(int argc, char* argv[])
{
string srcCompare= "19991223123000";
string dstCompare= "19991223123000";
double iItem = 3600;
double iDiff;
GetDiffTime(srcCompare,dstCompare,iItem,iDiff);
cout<<"diff time is"<<iDiff<<endl;
char c;
c = getchar();
return 0;
}
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