Question

我写了一个 '简单' (花了我 30 分钟) 程序,将十进制数转换为二进制。我确信有很多更简单的方法,所以你能告诉我吗?这是代码:

#include <iostream>
#include <stdlib.h>
using namespace std;
int a1, a2, remainder;
int tab = 0;
int maxtab = 0;
int table[0];
int main()
{
    system("clear");
    cout << "Enter a decimal number: ";
    cin >> a1;
    a2 = a1; //we need our number for later on so we save it in another variable
    while (a1!=0) //dividing by two until we hit 0
    {
        remainder = a1%2; //getting a remainder - decimal number(1 or 0)
        a1 = a1/2; //dividing our number by two
        maxtab++; //+1 to max elements of the table
    }
    maxtab--; //-1 to max elements of the table (when dividing finishes it adds 1 additional elemnt that we don't want and it's equal to 0)
    a1 = a2; //we must do calculations one more time so we're gatting back our original number
    table[0] = table[maxtab]; //we set the number of elements in our table to maxtab (we don't get 10's of 0's)
    while (a1!=0) //same calculations 2nd time but adding every 1 or 0 (remainder) to separate element in table
    {
        remainder = a1%2; //getting a remainder
        a1 = a1/2; //dividing by 2
        table[tab] = remainder; //adding 0 or 1 to an element
        tab++; //tab (element count) increases by 1 so next remainder is saved in another element
    }
    tab--; //same as with maxtab--
    cout << "Your binary number: ";
    while (tab>=0) //until we get to the 0 (1st) element of the table
    {
        cout << table[tab] << " "; //write the value of an element (0 or 1)
        tab--; //decreasing by 1 so we show 0's and 1's FROM THE BACK (correct way)
    }
    cout << endl;
    return 0;
}

顺便说一句，这很复杂，但我尽力了。

编辑-这是我最终使用的解决方案：

std::string toBinary(int n)
{
    std::string r;
    while(n!=0) {r=(n%2==0 ?"0":"1")+r; n/=2;}
    return r;
}

191

52

17

12

Answer 1

std::bitset有一个.to_string()方法，该方法返回一个std::string，其中包含二进制文本表示形式，并带有前导零填充。

根据数据需要选择 bitset 的宽度，例如std::bitset<32>从 32 位整数中获取 32 个字符的字符串。

#include <iostream>
#include <bitset>
int main()
{
    std::string binary = std::bitset<8>(128).to_string(); //to binary
    std::cout<<binary<<"\n";
    unsigned long decimal = std::bitset<8>(binary).to_ulong();
    std::cout<<decimal<<"\n";
    return 0;
}

编辑：请不要编辑我的答案为八进制和十六进制。

Answer 2

以下是一个递归函数，它接受一个正整数并将其二进制数字打印到控制台。

Alex 建议，为了提高效率，您可能希望删除printf()并将结果存储在内存中...根据存储方法，结果可能会反转。

/**
 * Takes a unsigned integer, converts it into binary and prints it to the console.
 * @param n the number to convert and print
 */
void convertToBinary(unsigned int n)
{
    if (n / 2 != 0) {
        convertToBinary(n / 2);
    }
    printf("%d", n % 2);
}

贷记 UoA ENGGEN 131

* 注意：使用 unsigned int 的好处是它不能为负。

Answer 3

您可以使用 std::bitset 将数字转换为其二进制格式。

使用以下代码段：

std::string binary = std::bitset<8>(n).to_string();

我在 stackoverflow 本身上找到了这个。我正在附加link。

Answer 4

一个非常简单的解决方案来打印二进制：

#include <iostream>
using namespace std;
int main()
{
 int num,arr[64];
 cin>>num;
 int i=0,r;
 while(num!=0)
{
  r = num%2;
  arr[i++] = r;
  num /= 2;
}
for(int j=i-1;j>=0;j--){
 cout<<arr[j];
  }
}