#include <stdio.h>

void inputChar(char *str)
{
    printf("input array char <100: ");
    scanf("%s", str);
}
void revers(char *A)
{
    int j;
    for (j = 0; A[j] != '\0'; j++);
    j--;
    for (int i = 0; i <j; i++, j--)
    {
        char temp = A[i];
        A[i] = A[j];
        A[j] = temp;
    }
}
int charToDecInt(char *A)
{
    int summ = 0;
    for (int i = 0; A[i] != '\0'; i++)
    {        
        if ('0' <= A[i] && A[i] <= '9')
        {
            summ *= 10;
            summ += A[i] - '0';
        }
        else
        {
            summ += A[i]-'A'+10;
        }

    }
    return summ;
}
void decIntTohexString(int a, char *A)
{
    int j = 0;
    while (a != 0)
    {
        int r = a % 16;
        if (r >= 1 && r <= 9)
        {
            r += '0';
        }
        else 
        {
            r += 'A'- 10;
        }
        A[j++] = r+A[j];
        a /= 16;
    }
    A[j] = '\0';
    revers(A);
}
void display()
{
    const int N = 100;
    char A[100] = {};
    char B[100] = {};
    inputChar(A);
    int a = charToDecInt(A);
    decIntTohexString(a, B);
    printf("hexChar = %s\n", B);
}
int main()
{
    display();
    return 0;
}