Example of hand execution techinque:

6) Stack Algorithms. Hand-execute the following algorithm that evaluates fully parenthesized infix arithmetic expressions. This algorithm uses 2 stacks, one stack for operands, and one stack for operators. Redraw each stack after each change of state. Use the following expression: while (c-readcharacter) if (c is a number) nums. push (c); if (c is an operand) ops.push (c); if (c is a right parenthesis) num1 = nums . pop(); num2 = nums . pop(); op ops.pop ) ans -num2 op num1; nums.push (ans); if (c is a left parenthesis) do nothing; ans pop ( )