/in/foo.cc:22:31: error: ISO C++ forbids declaration of 'Output' with no type [-fpermissive]
 Output(int A[N][N],int m,int n)
                               ^
/in/foo.cc: In function 'int Output(int (*)[100], int, int)':
/in/foo.cc:31:1: warning: no return statement in function returning non-void [-Wreturn-type]
 } 
 ^