Compilare: main.cpp: In function 'void solve()': main.cpp:119:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cycle.size() != 2 * n) ~~~~~~~~~~~~~^~~~~~~~ main.cpp: In function 'void read_arb(int, std::vector<int>*, int*)': main.cpp:19:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ main.cpp: In function 'void read(int&)': main.cpp:28:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:39:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ main.cpp: In function 'int main()': main.cpp:130:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dungeon.in", "r", stdin); ^ main.cpp:131:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dungeon.out", "w", stdout); ^ main.cpp:134:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^