Write pseudocode and draw flowchart to accept numbers till the user enters 0 and then find their average.

Question

Accepted Answer

> [!TLDR]
> When the number of inputs is not known in advance, a *sentinel value* (here 0) ends the loop: prime the first read before the loop, test the value, and re-read at the bottom so the sentinel is never added to the sum.

**The idea.** Contrast with the previous example: there the trip count (5) was known; here the user decides when to stop by typing 0. That calls for a **sentinel-controlled loop**. The classic shape is the *priming read*: input once before the loop, test, process, then input again at the end of the body. This guarantees the sentinel 0 is checked **before** it could be added to sum or counted.

**Pseudocode:**

```text
Step 1: SET sum = 0, count = 0
Step 2: INPUT num                       // priming read
Step 3: WHILE num is not equal to 0, REPEAT Steps 4-6
Step 4:     sum = sum + num
Step 5:     count = count + 1
Step 6:     INPUT num                   // read the next number
Step 7: IF count > 0 THEN
            average = sum / count
            PRINT average
        ELSE
            PRINT "No numbers were entered"
```

**Flowchart (nodes and arrows):**

1. **Start** (oval)
2. ↓ **sum = 0, count = 0** (rectangle)
3. ↓ **Input num** (parallelogram)
4. ↓ **Decision (diamond): "num = 0?"**
   - **No** → **sum = sum + num** (rectangle) → **count = count + 1** (rectangle) → **Input num** (parallelogram) → arrow back to the decision
   - **Yes** → step 5
5. ↓ **average = sum / count** (rectangle)
6. ↓ **Output average** (parallelogram)
7. ↓ **Stop** (oval)

**Python implementation:**

```python
total = 0
count = 0
num = int(input("Enter number (0 to stop): "))
while num != 0:
    total = total + num
    count = count + 1
    num = int(input("Enter number (0 to stop): "))
if count > 0:
    print("Average =", total / count)
else: …

Q.Write pseudocode and draw flowchart to accept numbers till the user enters 0 and then find their average.

Concept understanding — Iteration With Condition

Iteration With Condition

The Intuition

The Precise Statement

A Concrete Example

Q.Write pseudocode and draw flowchart to accept numbers till the user enters 0 and then find their average.

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