BIT移位运算符不起作用

Question

The variable z has been declared as long long unsigned int so the range is 0 to 18,446,744,073,709,551,615 but the following program fails to compute the required values after some iterations.

#include<stdio.h>

int main()
{
    long long unsigned int z=2;

    int i;

    for(i=0;i<40;i++)
    {
        printf("%d\n",z<<i);
    }

    return 0;
}

Answer 1

The problem is with your printf statement.

Updated code

#include <iostream>

int main()
{
    long long unsigned int z = 2;

    int i;

    for (i = 0; i<40; i++)
    {
        std::cout << (z << i) << "\n";
    }

    return 0;
}

Output

2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
65536
131072
262144
524288
1048576
2097152
4194304
8388608
16777216
33554432
67108864
134217728
268435456
536870912
1073741824
2147483648
4294967296
8589934592
17179869184
34359738368
68719476736
137438953472
274877906944
549755813888
1099511627776

Answer 2

尝试printf("%llu\\n",z<<i);

Answer 3

That's because %d is for printing int , not larger types.

The following works:

#include <iostream>

int main()
{
    long long unsigned int z=2;

    for (int i = 0; i < 40 ; i++)
    {
       std::cout << (z<<i) << "\n";
    }
}

Answer 4

您应该在printf格式化字符串中使用"%lld\\n" ，而不是"%d\\n" 。