/in/foo.cc: In function 'int main()':
/in/foo.cc:20:27: warning: too many arguments for format [-Wformat-extra-args]
   printf("x^%d",xishu[n],n);
                           ^
/in/foo.cc:24:28: warning: too many arguments for format [-Wformat-extra-args]
   printf("-x^%d",xishu[n],n);
                            ^
/in/foo.cc:7:19: warning: unused variable 'j' [-Wunused-variable]
  int xishu[400],i,j,n;
                   ^