[day_040421] binary conversion

Hexadecimal conversion

Title source

Cattle from ： Hexadecimal conversion

Title Description

Given a decimal number M, And the base number to be converted N. Will decimal number M Turn into N Hexadecimal number

Input description

Enter as one line ,M(32 An integer )、N(2 ≤ N ≤ 16), Space off .

Output description

Output the converted number for each test instance , One line per output . If N Greater than 9, The corresponding number rules refer to 16 Base number （ such as ,10 use A Express , wait ）

Example 1

Input

7 2

Output

111

Thought analysis

• The basic idea of binary conversion is to take modules , Then divide by the base to convert , Until the result of division is 0
• Mark negative numbers ,0 Print results directly
• The result of division is greater than 10 Number of numbers , Use ABCD Equal letter representation , So use string Save the final result
• Define a string to store 0-F,16 A digital , The result of the calculation is mapped to the array to get the corresponding value
• No result is spliced into the string , Finally, reverse the string , And print the results

Code display

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main()
{
    
	int m = 0;
	int n = 0;
	string num = "0123456789ABCDEF";// Result set mapping table 
	while (cin >> m >> n)
	{
    
		string str = "";

		//m by 0
		if (m == 0)
		{
    
			cout << '0';
			continue;
		}
		int flag = 0;// Mark positive and negative 
		if (m < 0)
		{
    
			flag = 1;
			m = -m;
		}
		while (m)
		{
    
			// The method of binary conversion , modulus , Divide by the decimal number to convert , Until the result is 0
			int temp = m % n;
			str += num[temp];
			m /= n;
		}
		if (flag)
		{
    
			str += '-';
		}
		// Inverse string 
		reverse(str.begin(), str.end());
		cout << str << endl;
	}
	return 0;
}