Compilare: user.cpp: In function ‘void main2()’: user.cpp:5:6: warning: variable ‘x’ set but not used [-Wunused-but-set-variable] int x[1000000]; ^ user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adunare.in", "r", stdin); ^ user.cpp:9:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adunare.out", "w", stdout); ^ user.cpp:11:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^