Compilare: user.cpp: In member function ‘void InputReader::advance()’: user.cpp:31:51: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:9:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In function ‘int main()’: user.cpp:43:19: warning: ‘i’ may be used uninitialized in this function [-Wmaybe-uninitialized] int a,b,s,i; ^ user.cpp:53:28: warning: ‘s’ may be used uninitialized in this function [-Wmaybe-uninitialized] s+=sa,s+=sb; ^ user.cpp:52:32: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] a+=sa*P,b+=sb*P; ^ user.cpp:50:42: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(a < v[i]-P) sa=(v[i]-P-a-1)/P+1; ^