/in/foo.c: In function 'main':
/in/foo.c:10:13: warning: implicit declaration of function 'min' [-Wimplicit-function-declaration]
  side_lenth=min(n,m);
             ^~~
/in/foo.c:19:2: error: expected ';' before 'for'
  for(i=1;i<=n;i++)
  ^~~
/in/foo.c:31:8: error: 'flags' undeclared (first use in this function)
  while(flags==0)
        ^~~~~
/in/foo.c:31:8: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:38:9: error: 'i' undeclared (first use in this function)
     for(i=k;i<=k+side_lenth-1;i++)
         ^
/in/foo.c:40:10: error: 'j' undeclared (first use in this function)
      for(j=q;j<=q+side_lenth;j++)
          ^
/in/foo.c:57:23: warning: format '%d' expects argument of type 'int', but argument 2 has type 'int *' [-Wformat=]
  printf("边长为：%d",&side_lenth);
                       ^
/in/foo.c:16:6: warning: variable 'a' set but not used [-Wunused-but-set-variable]
  int a[n][m];
      ^