Compilare: main.cpp: In function 'void dfs(int)': main.cpp:25:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < graph[x].size(); i++) { ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:41:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &N, &M); ^ main.cpp:44:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &x, &y); ^