Compilare: user.cpp: In function ‘void Query()’: user.cpp:72:15: warning: unused variable ‘t’ [-Wunused-variable] int k, i, t, len; ^ user.cpp:73:10: warning: unused variable ‘ok’ [-Wunused-variable] bool ok; ^ user.cpp: In function ‘void Read_and_Set()’: user.cpp:15:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S1); gets(S2); ^ user.cpp:15:23: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S1); gets(S2); ^ user.cpp: In function ‘void Query()’: user.cpp:75:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(Q); len = strlen(Q); //printf("%s ",Q); ^ user.cpp: In function ‘int main()’: user.cpp:125:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); gets(Q); ^ user.cpp:125:29: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); gets(Q); ^ /tmp/ccvHNOdi.o: In function `Read_and_Set()': user.cpp:(.text+0x17): warning: the `gets' function is dangerous and should not be used.