neconex.cpp: In function 'void read()': neconex.cpp:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result neconex.cpp:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result neconex.cpp: In function 'int bfs(int)': neconex.cpp:48: warning: comparison between signed and unsigned integer expressions neconex.cpp: In function 'int main()': neconex.cpp:111: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result neconex.cpp:112: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result neconex.cpp:113: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result