差分方程式

gistfile1.txt

x(i) = x(i - 1) + x(i - 2)

現況
private i = 2;
private int[] x = new int[i + 1];

void func() {
    x[i] = x[i - 1] + x[i - 2];
    
    //update buffer
    x[i - 2] = x[i - 1]; //x[1] <= x(i - 2)
    x[i - 1] = x[i]; //x[0] <= x(i - 1)
}

期望

private int x;

void func() {
    x(i) = x(i - 1) + x(i - 2);
}