foo.c: In function 'main':
foo.c:6:10: error: 'i' undeclared (first use in this function)
  int n,a[i];
          ^
foo.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
foo.c:8:3: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
  n=strlen a[i];
   ^
foo.c:8:11: error: expected ';' before 'a'
  n=strlen a[i];
           ^
foo.c:14:13: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    a[i]=temp,temp=a[i+1],a[i+1]=a[i];
             ^
foo.c:14:25: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    a[i]=temp,temp=a[i+1],a[i+1]=a[i];
                         ^
foo.c:6:8: warning: unused variable 'a' [-Wunused-variable]
  int n,a[i];
        ^

自豪的采用jd5进行评测(github.com/masnn/jd5)