Compilare: user.cpp: In function ‘int main()’: user.cpp:52:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2, l = 0; i <= str[p].length(); ++i) { ^ user.cpp:65:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1, l = 0; i <= str[q].length(); ++i) { ^ user.cpp:71:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (l == str[p].length()) { ^ user.cpp:26:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbnr.in" , "r", stdin ); ^ user.cpp:27:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbnr.out", "w", stdout); ^ user.cpp:30:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &t); ^ user.cpp:34:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:39:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^