Compilare: main.cpp: In function 'void dfs(int)': main.cpp:97:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[start_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:104:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.in", "r", stdin); ^ main.cpp:105:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.out", "w", stdout); ^ main.cpp:108:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &q); ^ main.cpp:109:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ main.cpp:116:66: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %c%c%c%c\n", &x, &y, &c1, &c2, &c3, &c4); ^ main.cpp:138:62: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %c%c%c%c\n", &x, &y, &c1, &c2, &c3, &c4); ^