foo.c: In function 'main':
foo.c:42:6: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
   K-=abs(k0-k)+abs(l0-l);
      ^~~
foo.c:11:17: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int k0,l0=-1,k,l;
                 ^
foo.c:36:12: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
   num[k][l]=-1;//记录最大值，然后置为0   
   ~~~~~~~~~^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)