Release版本下形如如下的递归代码会被编译器优化：
// No stack overflow in release version, can be optimized.
void RecursiveTail(int i)
{
RecursiveTail(++i);
}
// Stack overflow, cannot be optimized.
void RecursiveOver(int i)
{
RecursiveOver(i);
RecursiveOver(i);
}
使用可以被编译器优化的尾递归，不会产生栈溢出，可以提高执行效率。
#include <stdio.h>
// 递归求阶乘
unsigned int Refactorial(unsigned int i)
{
if(i == 0)
return 1;
return i * Refactorial(i-1);
}
// 循环求阶乘
unsigned int RefactorialLoop(unsigned int i)
{
int r = 1;
while(i!=1)
{
r *= i;
--i;
}
return r;
}
// 尾递归求阶乘
unsigned int RefactorialTail(unsigned int i, unsigned int status)
{
if(i == 0)
return status;
return RefactorialTail(i-1, status*i);
}
// 递归求菲波纳锲数列
unsigned int Febo(unsigned int i)
{
if(i < 2)
return i;
return Febo(i-1) + Febo(i-2);
}
// 循环求菲波纳锲数列
unsigned int FeboLoop(unsigned int i)
{
unsigned int x1 = 1; // 上上次结果
unsigned int x2 = 1; // 上一次结果
unsigned int result = 1; // 当前结果
if(i < 3)
return 1;
for(int j=3; j<=i; ++j)
{
x1 = x2; //1, 1, 2
x2 = result; //1, 2, 3
result = x1 + x2; //2, 3, 5
}
return x1 + x2;
}
// 尾递归求菲波纳锲数列
unsigned int FeboTail(unsigned int i,
unsigned int s1, //上上次结果
unsigned int s2) //上次结果
{
if(i == 0)
return s1;
return FeboTail(i-1, s2, s1+s2);
}
int main()
{
unsigned int i = Refactorial(25);
printf("\n%u\n", i);
i = RefactorialLoop(25);
printf("\n%u\n", i);
i = RefactorialTail(25, 1);
printf("\n%u\n", i);
i = FeboLoop(45);
printf("\n%u\n", i);
i = FeboTail(45, 0, 1);
printf("\n%u\n", i);
return 0;
}