arb1.cpp: In constructor 'instream::instream(const char*)': arb1.cpp:16: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result arb1.cpp: In constructor 'instream::instream(const char*)': arb1.cpp:16: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result arb1.cpp: In constructor 'instream::instream(const char*)': arb1.cpp:16: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result arb1.cpp: In member function 'void instream::advance()': arb1.cpp:42: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result arb1.cpp: In function 'void dfsadd(int, int, int)': arb1.cpp:52: warning: comparison between signed and unsigned integer expressions arb1.cpp:51: warning: unused variable 'd' arb1.cpp: In function 'void dfssolve(int, int, int)': arb1.cpp:70: warning: comparison between signed and unsigned integer expressions arb1.cpp:78: warning: comparison between signed and unsigned integer expressions arb1.cpp: In function 'int main()': arb1.cpp:87: warning: unused variable 'j'