Compilare: main.cpp: In function 'void compute(int)': main.cpp:45:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < adj[v].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void dfs(int, int)': main.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < adj[v].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void solve(int, int)': main.cpp:76:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < adj[v].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:103:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbore9.in", "r", stdin); ^ main.cpp:104:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbore9.out", "w", stdout); ^ main.cpp:108:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:110:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &a, &b, &c, &d); ^