#include <iostream>
using namespace std;
int main()
{int year;
bool leap;
cout <<"please enter year:";
cin >> year;
if(year%4==0)

{
if(year%100==0)
{
if(year%400==0)
      

         leap=true;

               else leap=false;

}
else
leap=true;}
else
  leap=false;

if(leap)
cout << year << "is";
else
   cout << year << "is not";
cout << "a leap year." << endl;
return 0;

}

什么叫“到EXE出现错误”，你得说别人能听得懂的话呀！

另外，最重要的是『排版』，否则下次没人搭理你，给你个demo

#include <iostream>
using namespace std;

int main()
{
    int year;
    cout << "please enter year:";
    cin >> year;

    bool leap = year%400==0 || (year%4==0 && year%100!=0);

    cout << "year is " << (leap?"":"not ") << "a leap year." << endl;

    return 0;
}