foo.c:1:19: warning: extra tokens at end of #include directive
 #include <stdio.h>int f(n){if(n==1||n==2) return 1;
                   ^
foo.c:2:2: error: expected identifier or '(' before 'else'
  else return f(n-1)+f(n-2);}int main(){
  ^
foo.c:2:28: error: expected identifier or '(' before '}' token
  else return f(n-1)+f(n-2);}int main(){
                            ^
foo.c: In function 'main':
foo.c:5:16: warning: implicit declaration of function 'f' [-Wimplicit-function-declaration]
  printf("%d\n",f(x));
                ^
foo.c:4:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&x);
  ^

自豪的采用 HydroJudger 进行评测(github.com/hydro-dev/HydroJudger)