Pseudocode

Simplified tradeoff between natural and programming language. Pseudocode is not unique. That is to say that it does not have rigid rules. Different people may have different pseudocode syntax.

• Step 1: Do something
• Step 2: Do something
• Step 3: Do something
• … : …

A sequential step is a single task; for example a 1 to x.

Ask a question that is answered with a logic answer. The answer can be true/false. For example:

if (x > 0) add 1 to x
else substract 1 from x

Iterative steps.

add 1/2 cup to mixture
while mixture is dry

(This will be filled at a later point.)

Example:

 472
+593

Conceptualise:

Let m => 1 be number of digits

a<sub>m-1</sub> a<sub>3</sub> a<sub>2</sub> a<sub>1</sub>

=== Algorithm ===
<code>
Step 1: get m (user provides m)
Step 2: get a<sub>m-1</sub>・・・a<sub>1</sub> a<sub>0</sub>, b<sub>m-1</sub>・・・b<sub>1</sub>b<sub>0</sub>
Step 3: set i=0, set carry=0
Step 4: while(i ≤ m-1) do Step 5 to 7
Step 5:   set c<sub>i</sub> = a<sub>i</sub> + b<sub>i</sub> + carry
Step 6:   if(c<sub>i</sub> ≥ 10) then
            set c<sub>i</sub> = c<sub>i</sub> - 10
            set carry = 1
          else
            set carry = 0
Step 7:   set i = i + 1
Step 8: set c<sub>m</sub> = carry
step 9: print c<sub>m</sub> c<sub>m-1</sub> ... c<sub>2</sub> c<sub>1</sub> c<sub>1</sub>
step 10: stop

• Inputs: Get “variable”
  • Ex: get m, get radius
• Computation: set “variable” = expression
  • Ex: set area = π*radius²
• Output: print “variable”
  • Ex: print area

do
    op1
    op2
    op3
while(condition)

* Do while loops will execute at least once, online while loops

Data set of N elements: 13 4 -20 45 112 ・・・ N=10¹³ / 38944 Therefore the list will be L₁, L₂, L₃… L_N Target: 45 〇　130 × This is easy for the brain because the brain is made pattern matching.

Step 1 get L1, L2, LN, N, Target
Step 2 Set Found = No
Step 3 Set i = 1
Step 4 while (Foundo = No AND i ≤ N) do Step 5 to Step 6
Step 5     if (Li = Target) then
               set Found = Yes
Step 6     else
               set i = i + 1
Step 7 if (Found = Yes) then
           print "Target found"
Step 8 else
           print "Target not found"
Step 9 stop

x y 5 3 Swap the content of both variable so that X=3 and Y=5

Step 1 get x, y
Step 2 set temp = x
Step 3 x = y
Step 4 y = temp
Stop 5 Stop

* For swapping in other algorithm swap(x,y) can be used instead.

n ≥ 1 1+2+3+4+…+n

Formula: $\frac{(n+1)*n}{2}$ $\Theta$ (double check this information) When talking about efficiency we say that the efficiency of n is $\Theta(n^2)$