Compilare: user.cpp: In function ‘int main()’: user.cpp:26:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (k<S[i-1].size() && S[i-1][k] < element) ^ user.cpp:28:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k<S[i-1].size() && S[i-1][k] == element) { ^ user.cpp:36:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<S[N-1].size(); ++i) { ^ user.cpp:11:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ausoara.in", "rt", stdin); ^ user.cpp:14:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:15:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^ user.cpp:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &element); ^ user.cpp:23:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^ user.cpp:25:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &element); ^