Compilare: main.cpp: In function 'void dfs(int)': main.cpp:16:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[nod].size(); i++){ ~^~~~~~~~~~~~~~ main.cpp:22:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<g[nod].size()-2 || (i==g[nod].size()-2 && viz[g[nod][i+1].y]==0)){ ~^~~~~~~~~~~~~~~~ main.cpp:22:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<g[nod].size()-2 || (i==g[nod].size()-2 && viz[g[nod][i+1].y]==0)){ ~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:38:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("riremito.in", "r", stdin); ^ main.cpp:39:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("riremito.out", "w", stdout); ^ main.cpp:41:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:43:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^ main.cpp:49:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &q); ^ main.cpp:51:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^