0001 #include<iostream>
0002 using namespace std;
0003 
0004 uint64_t powerBF(uint64_t, int);
0005 uint64_t power(uint64_t, int);
0006 uint64_t power2BF_I(int);
0007 uint64_t power2_I(int);
0008 uint64_t power2BF(int);
0009 uint64_t power2(int);
0010 
0011 int main(int argc, char* argv[]) { //测试Power
0012    uint64_t a; int r;
0013    if (3 > argc) {  cout << "Usage: " << argv[0] << "<base><exponent>" << endl; return 1;  } //检查参数
0014    a = _atoi64(argv[1]); r = atoi(argv[2]); //获取输入
0015    printf("\n2 ^ %d  =  %I64d  =  %I64d\n\n", r, power2BF_I(r), power2_I(r)); //迭代版
0016    printf("\n2 ^ %d  =  %I64d  =  %I64d\n\n", r, power2BF(r), power2(r)); //递归版
0017    printf("\n%I64d ^ %d  =  %I64d  =  %I64d\n\n", a, r, powerBF(a, r), power(a, r)); //通用算法迭代版
0018    return 0;
0019 }