HexaDecimal to Binary C Program

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

int main()
{
    char hex[1000];
    int i, j;
    printf("Enter a HexaDecimal Number: ");
    scanf("%s",hex);
    j = strlen(hex);
    printf("Equivalent Binary Number is: ");
    for(i=0;i<j;i++){
        switch(hex[i]){
        case '0':
            printf("0000");
            break;
        case '1':
            printf("0001");
            break;
        case '2':
            printf("0010");
            break;
        case '3':
            printf("0011");
            break;
        case '4':
            printf("0100");
            break;
        case '5':
            printf("0101");
            break;
        case '6':
            printf("0110");
            break;
        case '7':
            printf("0111");
            break;
        case '8':
            printf("1000");
            break;
        case '9':
            printf("1001");
            break;
        case 'A':
            printf("1010");
            break;
        case 'B':
            printf("1011");
            break;
        case 'C':
            printf("1100");
            break;
        case 'D':
            printf("1101");
            break;
        case 'E':
            printf("1110");
            break;
        case 'F':
            printf("1111");
            break;
        case 'a':
            printf("1010");
            break;
        case 'b':
            printf("1011");
            break;
        case 'c':
            printf("1100");
            break;
        case 'd':
            printf("1101");
            break;
        case 'e':
            printf("1110");
            break;
        case 'f':
            printf("1111");
            break;
        }
    }
}