vector<Duration> durationTable; //it's the fee rule at time; 升序排列
time_t beginTime = x;
time_t endTime = y;
double calc(time_t beginTime, time_t endTime)
{
double result = 0;
//找到开始时段
int startDuration = 0;
for (vector<Duration>::iterator i = durationTable.begin(); i != durationTable.end(); ++i)
{
if (i->stopTime > beginTime)
break;
++startDuration;
}
//找到结束时段
int stopDuration = 0;
for (vector<Duration>::iterator i = durationTable.begin(); i != durationTable.end(); ++i)
{
if (i->stopTime >= endTime)
break;
++stopDuration;
}