Compilare: main.cpp: In function 'void dfs(int)': main.cpp:15:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:91:38: 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:92:40: 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:95:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &p, &n, &m); ^ main.cpp:98:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d ", &x, &y); ^ main.cpp:102:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^