Compilare: user.cpp: In function ‘int main()’: user.cpp:71:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("verlab.in", "r", stdin); ^ user.cpp:72:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("verlab.out", "w", stdout); ^ user.cpp:73:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &t); ^ user.cpp:76:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &n, &m); ^ user.cpp:78:83: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) scanf ("%d", &M[i][j]); ^