Compilare: user.cpp: In function ‘int main()’: user.cpp:34:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j <= strlen(s[NR - 1] + 1) ; ++j) ^ user.cpp:35:34: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[NR - 1][j] = NULL; ^ user.cpp:10:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("randuri.in", "r", stdin); ^ user.cpp:11:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("randuri.out", "w", stdout); ^ user.cpp:13:33: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s[NR] + 1, 101, stdin); ^