Multiple Choice Questions

Question 1

In 8-bit two's complement representation, the binary number 10101011 corresponds to which decimal value?

Options: A. 43 B. -85 C. -43 D. -84

Answer: B

Explanation: The most significnat bit indicates negativity. Covnerting from two's complement yields -85.

Question 2

What is the fundamental unit of computer data storage?

Options: A. bit B. Byte C. GB D. KB

Answer: B

Question 3

Which protocol is NOT related to email?

Options: A. POP3 B. SMTP C. WTO D. IMAP

Answer: C

Problem Solving

Question 21

A person starts at (0,0) facing the positive x-axis. Each round they move forward (increasing distance) and turn right. After 2017 rounds, what are their coordinates?

Answer: (1009, 1008)

Code Analysis

Question 23

#include <iostream>
using namespace std;

int main() {
    int freq[256] = {0};
    string input;
    cin >> input;
    
    for(char c : input) freq[c]++;
    for(char c : input) {
        if(freq[c] == 1) {
            cout << c << endl;
            return 0;
        }
    }
    cout << "no" << endl;
    return 0;
}

Input: "xyzxyw"

Output: z

Code Completion

Question 27-31 (Fast Exponentiation)

int fastPow(int x, int p, int m) {
    int result = 1;
    while(p > 0) {
        if(p % 2 == 1)
            result = (result * x) % m;
        p /= 2;
        x = (x * x) % m;
    }
    return result;
}

Question 32-36 (Rope Cutting)

int maxRopeLength(int ropes[], int n, int m) {
    int total = 0;
    for(int i=0; i<n; i++) total += ropes[i];
    
    if(total < m) return -1; // Failed
    
    int left = 1, right = 1000000;
    while(left < right) {
        int mid = (left + right + 1) / 2;
        int count = 0;
        for(int i=0; i<n; i++)
            count += ropes[i] / mid;
            
        if(count < m) right = mid - 1;
        else left = mid;
    }
    return left;
}