Compilare: user.cpp: In function ‘int cmp(char*, char*)’: user.cpp:18:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (strlen(b) != n) ^ user.cpp: In function ‘int In_hash(int, char*)’: user.cpp:41:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[x].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:51:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("criptare2.out", "w", stdout); ^ user.cpp:52:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:53:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:54:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] p = strtok(s, " "); ^ user.cpp:77:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] } ^ user.cpp: In function ‘void write()’: user.cpp:83:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:84:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] p = strtok(s, " "); ^ /tmp/ccMMErmg.o: In function `write()': user.cpp:(.text+0x1ab): warning: the `gets' function is dangerous and should not be used.