Unit 1 · Computer Basics and C++ Foundation

Start Here / 開始做題

1. Read Input and Output first. 中文：先找輸入及輸出。
2. Write down the variables you need. 中文：先決定變數。
3. Trace the sample once by hand. 中文：用範例手算一次。
4. Write, run, then compare every output character. 中文：執行後逐字比較輸出。

Unit Dashboard / 單元地圖

Computer Basics / 計算機概論

Storage Units / 儲存單位

C++ Starter Kit / C++ 入門

#include <iostream>
#include <iomanip>
using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    cout << a + b << '\n';
    return 0;
}

Yellow Syntax Guide / 黃色語法重點

Data Types and Operators / 資料型別及運算子

Operator Guide / 運算子完整導覽

| Bitwise / 位元 | & | ^ ~ | AND, OR, XOR, NOT on binary bits / 對二進位位元運算 | Use non-negative integers first. |

Bitwise Operators / 位元運算子

Computers store integers as binary bits. A bitwise operator compares or changes each bit position directly. 中文：位元運算子直接處理二進位的每一位。

Do Not Mix These / 不要混淆

Bitwise Dry Run / 位元手算

For a = 12 (1100₂) and b = 10 (1010₂):

Bit Masks / 位元遮罩

Count positions from the right: bit 0 is the rightmost bit. A mask has one 1 at the position to inspect or change. 中文：由右邊開始數，最右邊是 bit 0；遮罩只在目標位置放一個 1。

For ~, always state the width. This unit uses 8 bits in the NOT example so the output is predictable.

Operator Order / 運算次序

Common errors / 常見錯誤：write x == 5 to compare, but x = 5 to assign. Never divide by zero. For a decimal result, make at least one operand double.

Dry Run / 手算追蹤

For input 8 3, calculate 8+3=11, 8-3=5, 8*3=24 before coding. 中文：先手算範例，再寫程式。

Read This Before Coding / 學生自查

• Does every variable have a suitable type?
• Does the program read exactly the stated input?
• Does the output match the sample, including decimal places and line breaks?

Examples / 例題

Example 1-1 · Hello, F3!

Sample Input / 範例輸入

(no standard input)

Sample Output / 範例輸出

Hello, F3!

C++ focus / 語法重點：Use cout << "text" << '\n';.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    cout << "Hello, F3!\n";
    return 0;
}

Example 1-2 · Simple Calculator

Sample Input / 範例輸入

8 3

Sample Output / 範例輸出

11
5
24

C++ focus / 語法重點：Declare int a, b; and read with cin >> a >> b;.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    cout << a + b << '\n';
    cout << a - b << '\n';
    cout << a * b << '\n';
    return 0;
}

Example 1-3 · Average with Decimals

Sample Input / 範例輸入

80 75 90

Sample Output / 範例輸出

81.67

C++ focus / 語法重點：Use double average = (a + b + c) / 3.0; and fixed << setprecision(2).

Reference Answer / 參考答案

#include <iostream>
#include <iomanip>
using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    cout << fixed << setprecision(2) << (a + b + c) / 3.0 << '\n';
    return 0;
}

Example 1-4 · Odd or Even

Sample Input / 範例輸入

17

Sample Output / 範例輸出

Odd

C++ focus / 語法重點：Use % and if...else.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    if (n % 2 == 0) cout << "Even\n";
    else cout << "Odd\n";
    return 0;
}

Example 1-5 · Quotient and Remainder

Sample Input / 範例輸入

17 5

Sample Output / 範例輸出

3
2

C++ focus / 語法重點：Use / for quotient and % for remainder.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    cout << a / b << endl;
    cout << a % b << endl;
    return 0;
}

Example 1-6 · Minutes and Seconds

Sample Input / 範例輸入

367

Sample Output / 範例輸出

6 7

C++ focus / 語法重點：Use / and % with 60.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int s;
    cin >> s;
    cout << s / 60 << ' ' << s % 60 << endl;
    return 0;
}

Example 1-7 · Celsius to Fahrenheit

Sample Input / 範例輸入

25

Sample Output / 範例輸出

77.0

C++ focus / 語法重點：Use double; write 9.0 / 5 to avoid integer division.

Reference Answer / 參考答案

#include <iostream>
#include <iomanip>
using namespace std;

int main() {
    double c;
    cin >> c;
    cout << fixed << setprecision(1) << c * 9.0 / 5 + 32 << endl;
    return 0;
}

Example 1-8 · Update a Score

Sample Input / 範例輸入

50 12 7

Sample Output / 範例輸出

55

C++ focus / 語法重點：Use += and -= to update a variable.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int score, add, lose;
    cin >> score >> add >> lose;
    score += add;
    score -= lose;
    cout << score << endl;
    return 0;
}

Example 1-9 · Next Number

Sample Input / 範例輸入

99

Sample Output / 範例輸出

99
100

C++ focus / 語法重點：Use n++ after printing. It increases n by one.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    cout << n << endl;
    n++;
    cout << n << endl;
    return 0;
}

Example 1-10 · Larger Number

Sample Input / 範例輸入

8 13

Sample Output / 範例輸出

13

C++ focus / 語法重點：Use a > b ? a : b as a short two-choice expression.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    cout << (a > b ? a : b) << endl;
    return 0;
}

Example 1-11 · Number in Range

Sample Input / 範例輸入

42

Sample Output / 範例輸出

YES

C++ focus / 語法重點：Use && when both comparisons must be true.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    if (n >= 10 && n <= 99) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}

Example 1-12 · Access Check

Sample Input / 範例輸入

10 1

Sample Output / 範例輸出

Allow

C++ focus / 語法重點：Use || when either condition may be true.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int age, member;
    cin >> age >> member;
    if (age >= 12 || member == 1) cout << "Allow" << endl;
    else cout << "Deny" << endl;
    return 0;
}

Example 1-13 · Bitwise AND, OR and XOR

Sample Input / 範例輸入

12 10

Sample Output / 範例輸出

8
14
6

C++ focus / 語法重點：Use &, |, and ^. These are not logical && or ||.

Reference Answer / 參考答案

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    cout << (a & b) << endl;
    cout << (a | b) << endl;
    cout << (a ^ b) << endl;
    return 0;
}

Example 1-14 · Eight-Bit NOT

Sample Input / 範例輸入

13

Sample Output / 範例輸出

11110010

C++ focus / 語法重點：~n flips all bits. & 255 keeps only the last 8 bits. bitset<8> prints eight binary digits.

Reference Answer / 參考答案

#include <iostream>
#include <bitset>
using namespace std;

int main() {
    int n;
    cin >> n;
    cout << bitset<8>((~n) & 255) << endl;
    return 0;
}

ClassWork / 課後練習

Complete each task independently. Submit your C++ source file and one screenshot of successful output. 中文：獨立完成，提交程式碼及成功輸出截圖。

ClassWork 1-1 · Storage Estimate

Sample Input / 範例輸入

1

Sample Output / 範例輸出

357913941

C++ focus / 語法重點：Use integer division with long long. Encoding affects real storage size.

ClassWork 1-2 · Student Profile

Sample Input / 範例輸入

23001
Wing
15

Sample Output / 範例輸出

ID: 23001
Name: Wing
Age: 15

C++ focus / 語法重點：Use int, string, and cin.

ClassWork 1-3 · Division with Precision

Sample Input / 範例輸入

100 3

Sample Output / 範例輸出

33.33

C++ focus / 語法重點：Convert one operand to double or divide by 3.0.

ClassWork 1-4 · Rectangle Calculator

Sample Input / 範例輸入

8 3

Sample Output / 範例輸出

22
24

C++ focus / 語法重點：Perimeter is 2 * (L + W); area is L * W.

ClassWork 1-5 · Even Sum

Sample Input / 範例輸入

3 10

Sample Output / 範例輸出

28

C++ focus / 語法重點：Use a for loop and test i % 2 == 0.

ClassWork 1-6 · Four Operations

Sample Input / 範例輸入

20 6

Sample Output / 範例輸出

26
14
120
3

C++ focus / 語法重點：Use the four arithmetic operators. Keep both variables as int.

ClassWork 1-7 · School Bell Time

Sample Input / 範例輸入

125

Sample Output / 範例輸出

2 minutes 5 seconds

C++ focus / 語法重點：Use / 60 and % 60.

ClassWork 1-8 · Total Cost

Sample Input / 範例輸入

12 5 8

Sample Output / 範例輸出

60
68

C++ focus / 語法重點：First calculate P * Q; then use += D.

ClassWork 1-9 · Average Speed

Sample Input / 範例輸入

100 3

Sample Output / 範例輸出

33.33

C++ focus / 語法重點：Use fixed, setprecision(2), and divide by double(T).

ClassWork 1-10 · Temperature Difference

Sample Input / 範例輸入

18 25

Sample Output / 範例輸出

7

C++ focus / 語法重點：Use if...else and subtraction; do not assume the input order.

ClassWork 1-11 · Full Boxes

Sample Input / 範例輸入

53 12

Sample Output / 範例輸出

4 5

C++ focus / 語法重點：Use integer division and remainder.

ClassWork 1-12 · Pass Check

Sample Input / 範例輸入

49

Sample Output / 範例輸出

Fail

C++ focus / 語法重點：Use >=, not =. An if...else is suitable.

ClassWork 1-13 · Teenager Check

Sample Input / 範例輸入

15

Sample Output / 範例輸出

Teen

C++ focus / 語法重點：Join two comparisons with &&.

ClassWork 1-14 · Weekend Check

Sample Input / 範例輸入

6

Sample Output / 範例輸出

Weekend

C++ focus / 語法重點：Use || to combine the two weekend cases.

ClassWork 1-15 · Discount Price

Sample Input / 範例輸入

120

Sample Output / 範例輸出

108.00

C++ focus / 語法重點：Use if, *= 0.9, fixed, and setprecision(2).

ClassWork 1-16 · Three-Digit Number

Sample Input / 範例輸入

1000

Sample Output / 範例輸出

NO

C++ focus / 語法重點：Use both >= 100 and <= 999 with &&.

ClassWork 1-17 · Operator Practice Set (20 Sub-questions)

Check before submission / 提交前自查：Questions 11–20 use bitwise operators; do not replace & with && or | with ||.

Next Step / 下一步

Before Unit 2, you should be able to choose int or double, explain / and %, and distinguish && from &, and || from |. Redo Example 1-5 to 1-14 and ClassWork 1-17 if needed. 中文：進入 Unit 2 前，應能選擇合適型別，並正確使用基本運算子。