foo.cpp: In function 'int main()':
foo.cpp:19:13: error: 's1' was not declared in this scope
             s1=(double)i/j;
             ^
foo.cpp:21:54: error: 's2' was not declared in this scope
             if(s3>=0 && gcd((int)i,(int)j)==1 && s3<=s2)
                                                      ^
foo.cpp:13:12: warning: unused variable 'ans2' [-Wunused-variable]
     double ans2=0.0000;
            ^
foo.cpp:14:12: warning: unused variable 'ans3' [-Wunused-variable]
     double ans3=1000000.00;
            ^