Compilare: user.cpp: In function ‘int main()’: user.cpp:75:12: warning: unused variable ‘i’ [-Wunused-variable] int t, i; ^ user.cpp: In function ‘int id(char)’: user.cpp:32:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:73:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lru.in", "r", stdin); ^ user.cpp:74:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lru.out", "w", stdout); ^ user.cpp:77:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:81:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%s%s", &len, a + 1, b + 1); ^ user.cpp: In function ‘long long int solve()’: user.cpp:57:30: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(!q[pos].empty()) ^