Compilare: user.cpp: In function ‘int main()’: user.cpp:15:21: warning: unused variable ‘a’ [-Wunused-variable] int n, i, j, k, a, b, c; ^ user.cpp:15:24: warning: unused variable ‘b’ [-Wunused-variable] int n, i, j, k, a, b, c; ^ user.cpp:15:27: warning: unused variable ‘c’ [-Wunused-variable] int n, i, j, k, a, b, c; ^ user.cpp:12:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("royfloyd.in", "r", stdin); ^ user.cpp:13:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("royfloyd.out", "w", stdout); ^ user.cpp:16:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:20:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &drum[i][j]); ^