Compilare: main.cpp: In function 'int main()': main.cpp:17:10: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[n]=NULL; ^~~~ main.cpp:78:21: warning: unused variable 'cnt' [-Wunused-variable] int cnt=0; ^~~ main.cpp: In function 'int op1(int, int, char)': main.cpp:10:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.cpp: In function 'int main()': main.cpp:13:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.in","r",stdin); ^ main.cpp:14:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.out","w",stdout); ^ main.cpp:15:27: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(s+1,10005,stdin); ^ In file included from /usr/include/stdio.h:936:0, from /usr/include/c++/6/cstdio:42, from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46, from main.cpp:1: In function 'char* fgets(char*, int, FILE*)', inlined from 'int main()' at main.cpp:15:27: /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); ^