Compilare: user.cpp: In function ‘int main()’: user.cpp:21:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < given_nums.size(); i ++) { ^ user.cpp:22:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < given_nums.size(); j ++) { ^ user.cpp:23:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < given_nums.size(); k ++) { ^ user.cpp:9:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto.in", "r", stdin); ^ user.cpp:10:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto.out", "w", stdout); ^ user.cpp:13:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &s); ^ user.cpp:17:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &given_nums[i]); ^