qvect.cpp: In function 'int main()': qvect.cpp:57: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result qvect.cpp:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result qvect.cpp:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result qvect.cpp:66: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result qvect.cpp:69: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result qvect.cpp:75: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result qvect.cpp: In function 'void solve2(int, int)': qvect.cpp:31: warning: 'sol' may be used uninitialized in this function