Compilare: user.cpp: In function ‘void task2()’: user.cpp:86:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < v.size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:94:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("intrus.in", "r", stdin); ^ user.cpp:95:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("intrus.out", "w", stdout); ^ user.cpp:101:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &type); ^ user.cpp:103:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &N, &M, &D); ^ user.cpp:107:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &a[i][j]); ^