/in/foo.c:9:1: warning: return type defaults to 'int' [enabled by default]
 voidAllarrange(char *str,int k,int len)
 ^
/in/foo.c: In function 'voidAllarrange':
/in/foo.c:21:4: warning: implicit declaration of function 'Allarrange' [-Wimplicit-function-declaration]
    Allarrange(str,k+1,len);
    ^
/in/foo.c: In function 'main':
/in/foo.c:29:2: warning: 'gets' is deprecated (declared at /usr/include/stdio.h:638) [-Wdeprecated-declarations]
  gets(str);
  ^
/in/foo.c:30:2: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
  Allarrange(str,0,strlen(str)-1);
  ^
/in/foo.c:30:19: warning: incompatible implicit declaration of built-in function 'strlen' [enabled by default]
  Allarrange(str,0,strlen(str)-1);
                   ^
/in/foo.c: In function 'voidAllarrange':
/in/foo.c:25:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/tmp/ccl2TZCp.o: In function `main':
foo.c:(.text.startup+0xc): warning: the `gets' function is dangerous and should not be used.
/tmp/ccl2TZCp.o: In function `voidAllarrange':
foo.c:(.text+0x60): undefined reference to `Allarrange'
/tmp/ccl2TZCp.o: In function `main':
foo.c:(.text.startup+0x54): undefined reference to `Allarrange'
collect2: error: ld returned 1 exit status