apm.cpp: In function 'void dfs(int, int)': apm.cpp:13: warning: comparison between signed and unsigned integer expressions apm.cpp: In function 'int main()': apm.cpp:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result apm.cpp:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result