arbsum.cpp: In function 'int main()': arbsum.cpp:24: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result arbsum.cpp:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result arbsum.cpp:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result arbsum.cpp:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result arbsum.cpp: In function 'void DFS(int)': arbsum.cpp:46: warning: comparison between signed and unsigned integer expressions