Question

Describe an algorithm that interchanges the values of the variables xand y, using only assignments. What is the minimum number of assignment statements needed to do this?

Short answer

The required algorithm is:

$$\begin{gathered} tmp=x \\ x=y \\ y=tmp \end{gathered}$$

Step-by-step solution

Step 1

The algorithm that interchanges the values,

$$\begin{gathered} tmp=x \\ x=y \\ y=tmp \end{gathered}$$

Step 2

Store the temporary value in some variable.

Step 3

Substituteyin the value of x

Step 4

Again assignyas thevalue inx.

Step 5

Therefore, we need minimum 3 assignment statements.