foo.c: In function 'main':
foo.c:26:27: warning: 'j1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   sum2=fabs(i2-i1)+fabs(j2-j1)+sum2;
                         ~~^~~
foo.c:27:9: warning: 'i1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(sum2+i1+1+num<=k)
     ~~~~^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)