Compilare: user.cpp: In function ‘void op1(int)’: user.cpp:16:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<h[r].size(); j++) ^ user.cpp: In function ‘void op2(int)’: user.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<h[r].size(); j++) ^ user.cpp: In function ‘void op3(int)’: user.cpp:52:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<h[r].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:71:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hashuri.in","r",stdin); ^ user.cpp:72:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hashuri.out","w",stdout); ^ user.cpp:75:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d",&N); ^ user.cpp:80:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&tip,&a); ^