问题描述
十六进制数是在程序设计时经常要使用到的一种整数的表示方式。它有0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F共16个符号,分别表示十进制数的0至15。十六进制的计数方法是满16进1,所以十进制数16在十六进制中是10,而十进制的17在十六进制中是11,以此类推,十进制的30在十六进制中是1E。
给出一个非负整数,将它表示成十六进制的形式。
输入格式
输入包含一个非负整数a,表示要转换的数。0<=a<=2147483647
输出格式
输出这个整数的16进制表示
样例输入
30
样例输出
1E
代码1:
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
long long int a;
while(cin >> a)
cout << setiosflags(ios::uppercase) << hex << a << endl; //输出大写的十六进制
return 0;
}
代码2:
#include<iostream>
using namespace std;
string he;
void dec_to_hex(long long int a)
{
he = "";
while(1)
{
int mod = a % 16;
switch(mod)
{
case 0: he = "0" + he; a /= 16; break;
case 1: he = "1" + he; a /= 16; break;
case 2: he = "2" + he; a /= 16; break;
case 3: he = "3" + he; a /= 16; break;
case 4: he = "4" + he; a /= 16; break;
case 5: he = "5" + he; a /= 16; break;
case 6: he = "6" + he; a /= 16; break;
case 7: he = "7" + he; a /= 16; break;
case 8: he = "8" + he; a /= 16; break;
case 9: he = "9" + he; a /= 16; break;
case 10: he = "A" + he; a /= 16; break;
case 11: he = "B" + he; a /= 16; break;
case 12: he = "C" + he; a /= 16; break;
case 13: he = "D" + he; a /= 16; break;
case 14: he = "E" + he; a /= 16; break;
case 15: he = "F" + he; a /= 16; break;
default:break;
}
if(a == 0) break;
}
}
int main()
{
long long int a;
while(cin >> a)
{
dec_to_hex(a);
cout << he << endl;
}
return 0;
}