Compilare: user.cpp: In function ‘int fct(char*, char*)’: user.cpp:24:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<strlen(a);j++){ ^ user.cpp:27:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i>=strlen(b)) return 0; ^ user.cpp: In function ‘int main()’: user.cpp:40:28: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[i].nr[strlen(s[i].nr)-1]=NULL; ^ user.cpp:41:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(s[i].nr)>val||(strlen(s[i].nr)==val&&strcmp(s[i].nr,s[o].nr)<0)) val=strlen(s[i].nr),o=i; ^ user.cpp:41:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(s[i].nr)>val||(strlen(s[i].nr)==val&&strcmp(s[i].nr,s[o].nr)<0)) val=strlen(s[i].nr),o=i; ^ user.cpp:35:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d\n",&p,&n); ^ user.cpp:38:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s[i].nr,5006,f); ^ In file included from /usr/include/stdio.h:934:0, from user.cpp:1: In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘int main()’ at user.cpp:38:30: /usr/include/i386-linux-gnu/bits/stdio2.h:253:58: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer [enabled by default] return __fgets_chk_warn (__s, __bos (__s), __n, __stream); ^