Compilare: user.cpp: In function ‘int main()’: user.cpp:39:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (F[i]) ^ user.cpp:10:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("exp.in", "r", stdin); ^ user.cpp:11:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("exp.out","w", stdout); ^ user.cpp:13:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &m, &n); ^ user.cpp:16:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a); ^ user.cpp:44:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("exp.out", "w", stdout); ^