Thread: Help~~something went wrong with my encoding code

hi guys, im new to C programming here
i was given an assignment to encode a 60 characters string using a 2d array substitution box.

I have fix my code below to generate output from sbox[0] (row0),but it gave me numbers from sbox[3] instead,
even from sbox[3], the digit can be convert correctly but not from column a-f

Anyone knows which part goes wrong?

Code:

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


main()


{
    int box_id, i,col;
    char input[100] = { "1312e7972714d01a46664a3523366a2f58560b42c485853674561c360d77" };
    char sbox[8][16] = {
        { '2', '4', 'c', '5', '9', 'a', '3', '7', 'e', '1', '0', 'f', '8', '6', 'b', 'd' },
        { '7', 'e', 'a', '4', '1', 'd', '9', 'f', '2', 'b', '6', '0', 'c', '5', '8', '3' },
        { '3', '8', 'f', '1', 'a', '6', '5', 'b', 'd', 'e', '4', '2', '7', '0', '9', 'c' },
        { '8', 'f', '7', '9', '3', 'd', '4', 'b', 'c', '2', '0', 'a', '1', '5', '6', 'e' },
        { '1', 'f', '8', '3', 'c', '0', 'b', '6', '2', '5', '4', 'e', '9', 'a', '7', 'd' },
        { '1', 'd', 'f', '0', 'e', '8', '2', 'c', '7', '4', 'b', 'a', '3', '5', '9', '6' },
        { 'a', '3', '4', '7', 'b', '8', 'd', '2', '6', 'c', 'f', 'e', '0', '5', '1', '9' },
        { '3', 'c', '4', '2', '7', 'a', '0', '8', '5', 'b', 'f', '1', 'd', '6', '9', 'e' }
    };




    printf("%s", input);
    printf("\n\n");


    //srand(time(NULL));
    //box_id=rand()%7;
    //printf("%d\n\n\n",box_id);


    for (i = 0; i < 60; i++)
    {
        


        if (input[i]=='a')
        {
            col = 10;
        }


        else if (input[i] == 'b')
        {
            col = 11;
        }


        else if (input[i] == 'c')
        {
            col = 12;
        }


        else if (input[i] == 'd')
        {
            col = 13;
        }


        else if (input[i] == 'e')
        {
            col = 14;
        }


        else if (input[i] == 'f')
        {
            col = 15;
        }


        else
        {
            col = i;
        }
        printf("%c", sbox[0][input[col]]);
    }


    printf("\n\n");
    system("pause");