递归函数转非递归：int f(int n) 和 int g(int n) 的优化

int f(int n) { int result; int f1 = 1; int f2 = 1; if (n <= 1) return 1; for (int i = 2; i <= n; i++) { result = f1 + g(f2); f1 = f2; f2 = result; } return result; }

int g(int n) { int result; int g1 = 1; int g2 = 1; if (n <= 1) return 1; for (int i = 2; i <= n; i++) { result = f(g2) + g(g1); g1 = g2; g2 = result; } return result; }