怎樣使得一個數從右向左4~9位全是1:

int a = 222222;

int temp = ~(~0 << 6);// ~0 使用數的每一位全為1, 左移六位，使得最右邊6位全為0, 再取反，例前面全為0,后面6位為1.

a >>= 4;

a &= temp;

a <<= 4;

 

#include <iostream>

using namespace std;

int main() {
        int ref = 1 << 31;
        int a = 14;
        
        for (int i = 0; i < 32; i++) {
                cout << (a & ref? '1': '0');
                a <<= 1;
        }
        
        return 0;
}