acop.cpp: In function 'int main()': acop.cpp:21: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result acop.cpp:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result acop.cpp:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result acop.cpp:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result acop.cpp:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result acop.cpp:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result acop.cpp: In function 'void GenComb(int, int)': acop.cpp:68: warning: suggest explicit braces to avoid ambiguous 'else'