Compilare: user.c: In function ‘main’: user.c:47:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(ult, -1, sizeof ult); ^ user.c:47:3: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c: In function ‘readch’: user.c:20:10: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, BUFF, in); ^