Question

我是C ++编程的新手。我正在编写一个读取两个整数的程序，其中一个是十进制数N，另一个是我想要转换为的基本系统b。对于基数16，A表示10，B表示11，依此类推。

#include<iostream>
using namespace std;
string dec2b();
int N, b;
int rem =0;
int main(){
    cout<<"please input a decimal positive number: "; cin>>N;
    cout<<"please input the desired base: "; cin>>b;
    string s = dec2b();
    cout<<'"'<<N<<'"'<<" in base-10 system = \""<<s<<"\" in base-"<<b<<"system"<<endl;
    return 0;
}

string dec2b()
{
    string s = ""; 
        while(N>0)
        {

            if (b==16)
            {
                rem = N%b;
                if (rem>9)
                {
                    switch (rem)
                    {
                        case 10: s= "A" + s; break;
                        case 11: s= "B" + s; break;
                        case 12: s= "C" + s; break;
                        case 13: s= "D" + s; break;
                        case 14: s= "E" + s; break;
                        case 15: s= "F" + s; break;
                    }
                }
                else
                {
                    s = char(rem+48) +s;
                }
            }
            else
            {
                rem = N%b;
                s = char(rem+48) +s;
            }
        N = N/b;
        }
    if (s=="")
    {cout<<"0";}
    else 
    {cout<<s; }

    return s;
}

它运行良好，但为什么我得到此错误而不是整数N的原始值？

Answer 1

在N函数中设置b和main()本地，并将函数string dec2b()更改为string dec2b(int N, int b)。同时将int rem = 0移至dec2b函数。避免使用全局变量。

string dec2b(int N, int b);

int main() 
{
    int N, b; // <- add here
    cout << "please input a decimal positive number: "; cin >> N;
    cout << "please input the desired base: "; cin >> b;
    string s = dec2b(N, b); // <- change here
    cout << '"' << N << '"' << " in base-10 system = \"" << s.c_str() << "\" in base-" << b << " system" << endl;
    return 0;
}

string dec2b(int N, int b)
{
    int rem = 0;
    // ...
    // your code here
}

N = 14和b = 16的结果将是：的＆＃34; 14＆＃34;在base-10系统中=＆＃34; E＆＃34;在base-16系统中

Answer 2

要转换的数字作为字符串传递给函数，并且base是要转换数字的基础。

C ++程序，可以将小数转换为任何给定的底数

#include<bits/stdc++.h>
using namespace std;
// To return char for a value. For example '2' 
// is returned for 2. 'A' is returned for 10. 'B' 
// for 11 
char reVal(int num) 
{ 
if (num >= 0 && num <= 9) 
    return (char)(num + '0'); 
else
    return (char)(num - 10 + 'A'); 
} 

// Utility function to reverse a string 
void strev(char *str) 
{ 
int len = strlen(str); 
int i; 
for (i = 0; i < len/2; i++) 
{ 
    char temp = str[i]; 
    str[i] = str[len-i-1]; 
    str[len-i-1] = temp; 
} 
} 

// Function to convert a given decimal number 
// to a base 'base' and 
char* fromDeci(char res[], int base, int inputNum) 
{ 
int index = 0; // Initialize index of result 

// Convert input number is given base by repeatedly 
// dividing it by base and taking remainder 
while (inputNum > 0) 
{ 
    res[index++] = reVal(inputNum % base); 
    inputNum /= base; 
} 
res[index] = '\0'; 

// Reverse the result 
strev(res); 

return res; 
} 

int main() 
{ 
int inputNum = 282, base = 16; 
char res[100]; 
printf("Equivalent of %d in base %d is "
    " %s\n", inputNum, base, fromDeci(res, base, inputNum)); 
return 0; 
}

输出：以16为基数的282的等效值为11A

十进制到C ++中的任何基本转换代码

2 个答案: