Compilare: user.cpp: In function ‘int main()’: user.cpp:106:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[i].size() < k) ^ user.cpp:75:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.in", "r", stdin); ^ user.cpp:76:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.out", "w", stdout); ^ user.cpp:80:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d\n", &n, &m, &k); ^ user.cpp:83:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", a[i]); ^