Compilare: user.cpp: In function ‘int main()’: user.cpp:54:12: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] c[lg+1]=NULL; ^ user.cpp: In function ‘long long int rez(long long int, long long int)’: user.cpp:43:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:51:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lld %d",&lg,&q); ^ user.cpp:52:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(c+1,100012,f); ^ user.cpp:53:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(c+1,100012,f); ^ user.cpp:57:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lld",&poz); ^ In file included from /usr/include/stdio.h:936:0, from user.cpp:1: In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘int main()’ at user.cpp:52:24: /usr/include/x86_64-linux-gnu/bits/stdio2.h:261:58: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer return __fgets_chk_warn (__s, __bos (__s), __n, __stream); ^ In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘int main()’ at user.cpp:53:24: /usr/include/x86_64-linux-gnu/bits/stdio2.h:261:58: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer return __fgets_chk_warn (__s, __bos (__s), __n, __stream); ^