foo.c: In function 'main':
foo.c:8:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
    8 |  gets(str);
      |  ^~~~
In file included from /usr/include/stdio.h:867,
                 from foo.c:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:235:1: note: declared here
  235 | gets (char *__str)
      | ^~~~
foo.c: In function 'delete_me':
foo.c:17:9: warning: unused variable 'j' [-Wunused-variable]
   17 |  int i, j;
      |         ^
foo.c: In function 'main':
foo.c:8:2: warning: ignoring return value of 'gets', declared with attribute warn_unused_result [-Wunused-result]
    8 |  gets(str);
      |  ^~~~~~~~~
foo.c:9:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d%d", &si,&len);
      |  ^~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cc53vRMh.o: in function `main':
foo.c:(.text.startup+0x25): warning: the `gets' function is dangerous and should not be used.

[Hydro](https://hydro.ac)提供评测服务