this is what I came up with so far but my but being that the array is double it's a bit difficult getting the elements into string expression and passing it to my infix.
Code:
#include<stdio.h>
#include<stdlib.h>
#define MAXCOLS 80
int main()
{
const int num_operand =3;
const int num_operatr = 2;
const int strglen=num_operand+num_operatr;
char operand;
int i, j;
char string[MAXCOLS];
char getexp[strglen+1];
double array[3][3]={23.4,13,12,3,6.5,21,5,4,6};
printf("Enter an expression:\n");
fgets(getexp, sizeof getexp, stdin);
for(j=0; getexp[j] != '\0'; j++)
{
operand=getexp[j];
if(operand >= 'A' && operand <='Z')
string[j]=array[operand-(int)('A')];
else
string[j]=(char)operand;
}
string[j] ='\0';
printf("Expression\n");
printf("%s", string);
getchar();
return 0;
}