Compilare: user.cpp: In function ‘int main()’: user.cpp:46:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<A[i].size(); j++) ^ user.cpp:27:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lupu.in","r",stdin); ^ user.cpp:28:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lupu.out","w",stdout); ^ user.cpp:29:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&x,&l); ^ user.cpp:33:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&b,&a); ^