in-proc-out flowchart examples

List of common flowchart symbols

There are at least 5+1 symbols used as common flowchart symbols, which are oval, rectangle, arrow, diamond, parallelogram, and plus circle ¹, where the first is more to rectangle with rounded corners with some names, e.g. stadium, capsule, or pill ². Beside flowchart, there is an alternative known as algorithm, where both are tools to visualize the solution of a problem in computer programming and they differ from each other ³. Flowchart can also be made using code, e.g. Mermaid ⁴. Here examples of flowchart that only using input, process, and output symbols are given using Mermaid.

addition of two numbers

{{< mermaid >}}
flowchart LR
  B --> I --> P --> O --> E
  B(["Begin"])
  I[/"Read x, y"/]
  P["z = x + y"]
  O[/"Display z"/]
  E(["End"])
{{< /mermaid >}}

subtraction of two numbers

{{< mermaid >}}
flowchart LR
  B --> I --> P --> O --> E
  B(["Begin"])
  I[/"Read x, y"/]
  P["z = x &mdash; y"]
  O[/"Display z"/]
  E(["End"])
{{< /mermaid >}}

multiplication of two numbers

{{< mermaid >}}
flowchart LR
  B --> I --> P --> O --> E
  B(["Begin"])
  I[/"Read x, y"/]
  P["z = x &times; y"]
  O[/"Display z"/]
  E(["End"])
{{< /mermaid >}}

division of two numbers

{{< mermaid >}}
flowchart LR
  B --> I --> P --> O --> E
  B(["Begin"])
  I[/"Read x, y"/]
  P["z = x / y"]
  O[/"Display z"/]
  E(["End"])
{{< /mermaid >}}

difference of squares

There is a relation

$$\tag{1} a^2 - b^2 = (a + b)(a - b) $$

known as difference of squares ⁵.

{{< mermaid >}}
flowchart LR
  B --> I --> P1 --> P2 --> P3 --> O --> E
  B(["Begin"])
  I[/"Read a, b"/]
  P1["c = a + b"]
  P2["d = a &mdash; b"]
  P3["e = c &times; d"]
  O[/"Display e"/]
  E(["End"])
{{< /mermaid >}}

Above example using three process symbols, P1, P2, P3, that actually can be merged into single P, but they are displayed separated for clearer meaning.

other examples

Infinite number of examples using only input, process, and output symbols can be made. Following are other examples.

• Calculate area of rectangle, square, parallelogram, trapezium, trapezoid, diamond, kite, etc.
• Calculate density from mass and volume of various geometrical froms.
• Calculate percentage.

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