piata.cpp: In function 'void read()': piata.cpp:21: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result piata.cpp:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result piata.cpp: In function 'void write()': piata.cpp:51: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result piata.cpp: In function 'int solve()': piata.cpp:28: warning: 'x' may be used uninitialized in this function