spider.cpp: In function 'int main()': spider.cpp:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result spider.cpp:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result spider.cpp:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spider.cpp:47: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spider.cpp:43: warning: 'sol.punct::y' may be used uninitialized in this function spider.cpp:43: warning: 'sol.punct::x' may be used uninitialized in this function