Compilare: user.cpp: In function ‘char nextch()’: user.cpp:11:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^ user.cpp: In function ‘int main()’: user.cpp:67:71: warning: ‘p2’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf(fo,"%lld", Find_Product(1LL*n*n-p1+1)-Find_Product(n*n-p2+1)); ^ user.cpp:67:53: warning: ‘p1’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf(fo,"%lld", Find_Product(1LL*n*n-p1+1)-Find_Product(n*n-p2+1)); ^