pluton.cpp: In function 'int main()': pluton.cpp:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pluton.cpp:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pluton.cpp:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pluton.cpp:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pluton.cpp:33: warning: 'ap' may be used uninitialized in this function pluton.cpp:33: warning: 'istart' may be used uninitialized in this function