已知x2−yz=1,1≤x,y,z≤nx^2−yz=1,1≤x,y,z≤nx2−yz=1,1≤x,y,z≤n,给定正整数n的值，如何求解x,y,z为正整数解的个数？请给出O(nlogn)O(\sqrt{n}logn)O(nlogn)的算法
