c++求助大神，我这个代码编译通过了，但是运行的时候又说源文件未编译，其他的代码又能运行

Question

#include<iostream>#include<math.h>using namespace std;class cDate_t{public:cDate_t();cDate_t(int y,int m,int d):year(y),month(m),day(d){} //构造函数cDate_t operator+(int days) //实现对符号+的重载 {cDate_t d2;d2.day=this->day+days; //天数相加 d2.month=this->month; //月份暂且不变 d2.year=this->year; //年份暂且不变 }cDate_t operator-(int days) //实现对符号-的重载 {cDate_t d2;d2.day=abs(this->day-days);d2.month=this->month;d2.year=this->year;}int IsLeapYear(int y) //判断这一年是不是闰年//判断方法：一年能被4整除不能被100整出，能被400整除 {return(y%100!=0&&y%4==0)||(y%400==0);}void fd() //找到相加或相减之后的日期是什么时候 {cDate_t d0; if(IsLeapYear(d0.year)) //如果是闰年的话 {int d[]={31,29,31,30,31,30,31,31,30,31,30,31}; //2月份是29天 while(d0.day>d[d0.month-1]) //如果天数大于当月的天数 {d0.day-=d[d0.month-1]; //则天数要进行做差d0.month++; //月份增加 if(d0.month<13){continue;}if(d0.month==13) //如果月份增加至13的话，则从第二年开始 {d0.month=1; //月份从第二年的1月份开始 d0.year+=1; //年份增加1 }if(d0.day<=d[d0.month-1]){break;}}}else{int d[]={31,28,31,30,31,30,31,31,30,31,30,31}; //若不是闰年的话，2月份就是28天 while(d0.day>d[d0.month-1]){d0.day-=d[d0.month-1];d0.month++;if(d0.month<13){continue;}if(d0.month==13){d0.month=1;d0.year+=1;}if(d0.day<=d[d0.month-1]){break;}}}cout<<"Year:"<<" "<<d0.year<<"Month:"<<" "<<d0.month<<"Day:"<<" "<<d0.day<<endl;} private:int year;int month;int day;}; int main(){cout<<"please input the date:"<<" "<<endl;int a,b,c;cin>>a>>b>>c;cDate_t dm(a,b,c);cDate_t dd;cout<<"please input how many days you want to plus:"<<" ";int m;cin>>m;dd=dm-m;dd.fd();return 0;}