function exp2(base , power)
if (power = 0)
return 1
else if (power = 1)
return base
else if (mod(power, 2) = 0)
tmp exp2(base, power/2)
return tmp tmp
else
return base exp2(base,power-1)
此代码的reccurce关系是什么?在创建方程式时,我应该如何参考“if”,“else”条件?