使用scanf函数报内存错误

#include <iostream>
#include <stdio.h>
using namespace std;
class Date{
private:
    int year;
    int month;
    int day;
public:
    bool IsLeapYear();
    const void display();
    Date():year(1800),month(12),day(10){}
    Date(int a,int b,int c):year(a),month(b),day(c){}
    bool DateInput(){
        cout<<"请输入年份"<<"如：1900"<<endl;
        scanf("%d",this->year);
        while (this->year>9999||this->year<1000)
        {   cout<<"请重新输入年份"<<endl;
            scanf("%d",this->year);
        }
        cout<<"请输入月份"<<"如：12"<<endl;
        scanf("%d",this->month);
        while (this->month>12||this->month<1)
        {   cout<<"请重新输入月份"<<endl;
        scanf("%d",this->month);
        }
        cout<<"请输入日子"<<"如：25"<<endl;
        scanf("%d",this->day);
        while (this->day>31||this->month<1)
        {   cout<<"请重新输入日子"<<endl;
        scanf("%d",this->day);
        }

return 0;
    }
   

};
    bool Date::IsLeapYear(){
        if((year % 4 &&!( year %100)) || (year % 400 ))
    return 1;
    else
    return 0;
}
const void Date::display(){
   
    if (IsLeapYear()==1)
    {  
        cout<<this->year<<"is a leap year!"<<endl;
    }
    else
        cout<<this->year<<"is not a leap year!"<<endl;

}

void main(){
    Date date1(2008,12,2);
    Date date2(2000,12,2);
    Date date3(2100,12,2);
    date1.display();
    date2.display();
    date3.display();
    Date date4;
    date4.DateInput();
      
   

}