Compilare: user.cpp: In instantiation of ‘void solve(query*, T, std::function<int(query)>) [with T = std::less<int>]’: user.cpp:148:71: required from here user.cpp:111:15: warning: statement has no effect [-Wunused-value] for (j; j <= n && t(bring(q[j]), a[i].c); j++) ^ user.cpp: In instantiation of ‘void solve(query*, T, std::function<int(query)>) [with T = std::greater<int>]’: user.cpp:152:77: required from here user.cpp:111:15: warning: statement has no effect [-Wunused-value] user.cpp: In function ‘void read()’: user.cpp:41:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &m, &n, &k); ^ user.cpp:43:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:48:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:142:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninja.in", "r", stdin); ^ user.cpp:143:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninja.out", "w", stdout); ^