Compilare: user.cpp: In function ‘int main()’: user.cpp:69:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<f.size();i++) ^ user.cpp:80:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<f.size();i++) ^ user.cpp:37:32: 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:38:34: 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:49:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); ^ user.cpp:50:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:54:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^