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--- computer_science [2021/09/16 23:43] – [Case study: addition] mana
+++ computer_science [2021/09/25 05:27] (current) – mana
@@ Line 41: / Line 41: @@
-===== Algorithm =====
-==== Design ====
-  * Step 1: Do something
-  * Step 2: Do something
-  * Step 3: Do something
-  * ...   : ...
-==== Sequential steps ====
-A sequential step is a single task; for example ''%%a 1 to x%%''.
-==== Conditional steps ====
-Ask a question that is answered with a logic answer. The answer can be ''%%true%%''/''%%false%%''.
-For example:
-<code>
-if (x > 0) add 1 to x
-else substract 1 from x
-</code>
-==== Loops ====
-Iterative steps.
-<code>
-add 1/2 cup to mixture
-while mixture is dry
-</code>
-==== Recursion ====
-FIXME (This will be filled at a later point.)
-==== Case study: addition ====
-Example:
-<code>
-+593
-</code>
-----
-FIXME
-Conceptualise:
-<code>
-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
-</code>