/in/foo.cc: In function 'int Insert(int*, int, int)':
/in/foo.cc:20:7: warning: 'i' is used uninitialized in this function [-Wuninitialized]
  a[i+1]=x;
       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:20:8: warning: 'x' is used uninitialized in this function [-Wuninitialized]
  a[i+1]=x;
  ~~~~~~^~
/in/foo.cc:27:21: note: 'x' was declared here
  int a[10000] , n , x;
                     ^