Compilare: main.cpp: In function 'void dfs(int, int, int)': main.cpp:76:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < Va[st].size(); i++) ~~^~~~~~~~~~~~~~~ main.cpp:81:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < Va[st].size(); i++) ~~^~~~~~~~~~~~~~~ main.cpp:89:14: warning: unused variable 'y' [-Wunused-variable] for(auto y: aint[p]) Undo(); ^ main.cpp: In function 'char nextch()': main.cpp:11:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^