Compilare: user.cpp: In function ‘void dfs(int, bool, bool*)’: user.cpp:22:36: warning: suggest parentheses around comparison in operand of ‘^’ [-Wparentheses] if (!viz[i] && a[node][i] ^ st == 1 && in[i]) ^ user.cpp: In function ‘int main()’: user.cpp:70:43: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘std::vector<int>::size_type {aka long unsigned int}’ [-Wformat=] printf("%d\n%d\n", cost(ans), ans.size()); ^ user.cpp:56:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("soc.in", "r", stdin); ^ user.cpp:57:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("soc.out", "w", stdout); ^ user.cpp:58:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:61:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &e[i]); ^ user.cpp:66:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u, &v); ^