Compilare: main.cpp: In function 'int find_x(int)': main.cpp:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < H[h].size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:21:36: 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); ^ main.cpp:22:38: 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); ^ main.cpp:25:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:27:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &op, &x); ^