Compilare: main.cpp: In function 'void dfs(int)': main.cpp:64:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[nod].size(); i++){ ~^~~~~~~~~~~~~~ main.cpp: In function 'char read_ch()': main.cpp:88:33: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(_in_buff, 1, 4096, _fin); ^