c语言，输入一个32位二进制，转换为十六进制并输出

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    char binary[33];
    printf("请输入32位二进制数：");
    scanf("%s", binary);
    if (strlen(binary) != 32) {
        printf("输入错误！\n");
        return 0;
    }
    int i = 0, j = 0;
    char hex[9];
    while (i < 32) {
        int dec = (binary[i] - '0') * 8 + (binary[i + 1] - '0') * 4 
            + (binary[i + 2] - '0') * 2 + (binary[i + 3] - '0');
        if (dec < 10) {
            hex[j++] = dec + '0';
        } else {
            hex[j++] = dec - 10 + 'A';
        }
        i += 4;
    }
    hex[j] = '\0';
    printf("十六进制为：%s\n", hex);
    return 0;
}