Thread: Converting to expression to string of array elements

This code converts an expression A*B-C-D+E to 5*3-2-3+4 using the array elements but it seems to work for only single digits, can anyone assist me here, to make it work fr double digits?

Code:

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

#define MAXCOLS 80

int main()
{
   const int num_operand =5;
    const int num_operatr = 4;
   const int strglen=num_operand+num_operatr;
    char operand;
    int i, j;
    char string[MAXCOLS];
    char getexp[strglen+1];
    char a[]={'5','3','2','3','4','2','5','4','6','8'};
                 

    printf("Enter a command of the sort A+B*C_D*E:\n");
    fgets(getexp, sizeof getexp, stdin);

    for(j=0; getexp[j] != '\0'; j++)
    {
       operand=getexp[j];
       
       if(operand >= 'A' && operand <='Z')
           string[j]=a[operand-(int)('A')];
       else
           string[j]=(char)operand;
    }
    string[j] ='\0';

    printf("Expression\n");
    printf("%s", string);
    
    getchar();
    return 0;
 }