linie.cpp: In function 'void backt(int, int)': linie.cpp:62: warning: unused variable 'sd' linie.cpp: In function 'int main()': linie.cpp:79: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result linie.cpp:80: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result linie.cpp:82: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result linie.cpp:85: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result