dfs.cpp: In function 'void dfs1(int)': dfs.cpp:20: warning: suggest explicit braces to avoid ambiguous 'else' dfs.cpp: In function 'int main()': dfs.cpp:46: warning: format '%d' expects type 'int', but argument 2 has type 'long long int' dfs.cpp:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result dfs.cpp:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result dfs.cpp:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result dfs.cpp:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result