关于左移和右移的口算：
a 左移 n 位就是 a 乘 2 的 n 次方 a 右移 n 位就是 a 除 2 的 n 次方
unsigned int a = 60; // 60 = 0011 1100 c = a << 2; // 240 = 1111 0000 cout << "Line 5 - c 的值是 " << c << endl ; c = a >> 2; // 15 = 0000 1111 cout << "Line 6 - c 的值是 " << c << endl ;<br> c = a << 2; // 240 = 1111 0000 // c = a* 2^2 = a*4 = 60*4 c = a >> 2; // 15 = 0000 1111 // c = a/ 2^2 = a/4 = 60/4 c = a >> n; // c = a * (2^n); c = a << n; // c = a / (2^n);
给出测试代码：
#include <iostream>
#include <math.h>
using namespace std;
int left(int a,int n);
int right(int a,int n);
int main()
{
unsigned int a = 33;
cout << "关于a左移和右移n位的口算方法" << endl;
cout << "a << 2 =" << (a<<2) << endl;
cout << "a << 2 =" << (left(a,2)) << endl;
cout << "a >> 2 =" << (a>>2) << endl;
cout << "a >> 2 =" << (right(a,2)) << endl;
return 0;
}
int left(int a,int n){
return a * pow(2,n);
}
int right(int a,int n){
return a / pow(2,n);
}
运行结果：
关于a左移和右移n位的口算方法 a << 2 =132 a << 2 =132 a >> 2 =8 a >> 2 =8
