Session 10 Homework - Loops Mission

Loop	Use When	Real-Life Example	Memory Trick
for	You know how many times to repeat.	Print levels 1 to 10, show table 1 to 10.	for = fixed count
while	You do not know exact repetitions, depends on condition.	Ask password until correct.	while = condition first
do-while	You must run at least once.	Show menu once, then repeat if user wants.	do-while = do first, check later

Homework Missions

For each mission, read: Why this loop? then How to think then code and test.

Mission 1: XP Level Counter (for loop)

Print levels from 1 to N

Why for loop? We know exactly how many levels to print.

Thinking steps:

Take input N.
Start i from 1.
Repeat while i <= N.
Print level and increase i.

#include <stdio.h>

int main() {
    int n, i;
    printf("Enter max level: ");
    scanf("%d", &n);

    for (i = 1; i <= n; i++) {
        printf("Level %d unlocked!\n", i);
    }
    return 0;
}

n = 3 -> Level 1, Level 2, Level 3
n = 5 -> prints 5 levels

Mission 2: Sum and Average of Scores (for loop)

Add scores of N rounds and find average

Why for loop? Number of rounds is fixed (N rounds).

Technical concept: This is an accumulator pattern. sum = sum + value on each iteration.

#include <stdio.h>

int main() {
    int n, i, score, sum = 0;
    float avg;

    printf("How many rounds? ");
    scanf("%d", &n);

    for (i = 1; i <= n; i++) {
        printf("Enter score for round %d: ", i);
        scanf("%d", &score);
        sum += score;
    }

    avg = (float)sum / n;
    printf("Total = %d\n", sum);
    printf("Average = %.2f\n", avg);
    return 0;
}

Mission 3: Secret PIN System (while loop)

Keep asking until PIN is correct or attempts end

Why while loop? We do not know when user will enter correct PIN.

Important: Update attempt count every time, otherwise infinite loop happens.

#include <stdio.h>

int main() {
    int pin = 4321, entered, attempts = 0;

    while (attempts < 3) {
        printf("Enter PIN: ");
        scanf("%d", &entered);

        if (entered == pin) {
            printf("Access granted!\n");
            break;
        } else {
            attempts++;
            printf("Wrong PIN. Attempts left: %d\n", 3 - attempts);
        }
    }

    if (attempts == 3) {
        printf("Account locked.\n");
    }
    return 0;
}

Mission 4: Game Menu Loop (do-while)

Show menu at least once, continue until user exits

Why do-while? Menu must appear once before checking continue condition.

#include <stdio.h>

int main() {
    int choice;

    do {
        printf("\n=== GAME MENU ===\n");
        printf("1. Start Game\n");
        printf("2. Settings\n");
        printf("3. Exit\n");
        printf("Choose: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1: printf("Starting game...\n"); break;
            case 2: printf("Opening settings...\n"); break;
            case 3: printf("Goodbye!\n"); break;
            default: printf("Invalid choice.\n");
        }
    } while (choice != 3);

    return 0;
}

Mission 5: Star Map Builder (nested loops)

Print a rectangle map of stars using rows and columns

Why nested loops? Outer loop handles rows, inner loop handles columns.

2D thinking:

For each row
Print stars for each column
Move to next line

#include <stdio.h>

int main() {
    int rows, cols, r, c;
    printf("Enter rows and cols: ");
    scanf("%d %d", &rows, &cols);

    for (r = 1; r <= rows; r++) {
        for (c = 1; c <= cols; c++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

rows=3, cols=4 -> 3 lines, 4 stars each
rows=2, cols=5 -> 2 lines, 5 stars each

Mission 6: Loot Filter (continue + break)

Skip bad items and stop when bag is full

Why break/continue? continue skips unwanted items, break exits early.

#include <stdio.h>

int main() {
    int item, bagCount = 0;

    for (item = 1; item <= 20; item++) {
        if (item % 2 == 0) {
            continue; // skip even-numbered items
        }

        printf("Picked item %d\n", item);
        bagCount++;

        if (bagCount == 5) {
            printf("Bag full! Stop looting.\n");
            break;
        }
    }
    return 0;
}

Boss Challenge (mini project)

Create a Math Practice Game:

- Show menu with do-while (Play / Show Score / Exit)

- In Play mode, ask 5 questions using for loop

- Use while loop to re-ask if user types invalid input

- Use break if user wants to quit early

This one project makes you use all loops practically.

Session 10 Homework: Loops Mission

Fun + Practical + Technical (for a 13-year-old coder)

Game frame update

Leaderboard printing

Login attempts

Pattern generation

Mission 1: XP Level Counter (for loop)

Mission 2: Sum and Average of Scores (for loop)

Mission 3: Secret PIN System (while loop)

Mission 4: Game Menu Loop (do-while)

Mission 5: Star Map Builder (nested loops)

Mission 6: Loot Filter (continue + break)

Boss Challenge (mini project)

Final Loop Memory Rule