计算A(n,x,y)，当n<>0,y<>0时，用函数调用A(n,x,y-1)代替，其中B=A(n,x,y-1)。在计算A(n,x,y-1)前，应先将参数n,x,y保存起来，待计算出A(n,x,y-1)的值之后，设其值为B，再回来计算A(n,B,x)。如果计算出A(n,x,y-1)时，仍有y-1>0，又要将n,x,y-1保存起来，去计算A(n,x,y-2),...,直到能计算出值，再返回来计算各中间值反复进行这一过程，直到最后求得最初的函数值-calculation A (n, x, y), 4; Gt; 0, ylt; Gt; 0:00 a.m., with a function call A (n, x, y-1) to replace, B = A (n, x, y-1 ). In the calculation of A (n, x, y-1), before first parameter n, x, y saved, the question calculate A (n, x, y-1) value, based Value B, A calculation of return (n, B , x). If calculated A (n, x, y-1), there is still y-1gt; 0, but also to n, x, y-1 saved, the calculation of A (n, x, y-2 ),..., until value can be calculated and then back to calculate the median repeated the process, until the last strike initial function