Compilare: main.cpp: In function 'int main()': main.cpp:20:30: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[i][strlen(s[i]) - 1] = NULL; ^~~~ main.cpp:13:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("binar.in", "r", stdin); ^ main.cpp:14:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("binar.out", "w", stdout); ^ main.cpp:17:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &n, &m); ^ main.cpp:19:34: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(s[i] + 1, m + 2, stdin); ^