Compilare: user.cpp: In function ‘void solve()’: user.cpp:46:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = v.size() - 1; i == v.size() - 1 || v[i] != v.back(); --i) { ^ user.cpp: In function ‘void read_input()’: user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:21:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %c\n", &x[i], &y[i], &cul[i]); ^ user.cpp: In function ‘int main()’: user.cpp:60:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zaharel.in","r",stdin); ^ user.cpp:61:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zaharel.out","w",stdout); ^