Compilare: user.cpp: In function ‘int main()’: user.cpp:12:21: warning: unused variable ‘lna’ [-Wunused-variable] int n, m, a, b, lna = 0, cnt, rez; ^ user.cpp:12:30: warning: unused variable ‘cnt’ [-Wunused-variable] int n, m, a, b, lna = 0, cnt, rez; ^ 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("drept2.in", "r", stdin); ^ user.cpp:11:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("drept2.out", "w", stdout); ^ user.cpp:14:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &m, &n, &a, &b); ^