spiridusi.cpp: In function 'void compute(int)': spiridusi.cpp:49: warning: comparison between signed and unsigned integer expressions spiridusi.cpp: In function 'int main()': spiridusi.cpp:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result spiridusi.cpp:56: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result spiridusi.cpp:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spiridusi.cpp:60: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spiridusi.cpp:62: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spiridusi.cpp:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result spiridusi.cpp: In function 'void compute(int)': spiridusi.cpp:22: warning: 'up' may be used uninitialized in this function