Compilare: main.cpp: In function 'int main()': main.cpp:61:14: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] sol[n] = NULL; ^~~~ main.cpp:17:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balans2.in", "r", stdin); ^ main.cpp:18:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("balans2.out", "w", stdout); ^ main.cpp:21:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ main.cpp:22:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s); ^