foo.c: In function 'main':
foo.c:12:2: warning: statement with no effect [-Wunused-value]
  for(x;x<=y;x++)
  ^~~
foo.c:11:7: warning: iteration 98 invokes undefined behavior [-Waggressive-loop-optimizations]
   a[i]=a[i-1]+a[i-2];
   ~~~~^~~~~~~~~~~~~~
foo.c:10:2: note: within this loop
  for(int i=2;i<=100;i++)
  ^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)