Embercode: AI-powered software engineer course

1. What does this program print? ``

cpp
#include <iostream>
#include <vector>

int main() {
    std::vector<std::vector<long long>> g{{1, 2, 3}, {4, 5, 6}};
    std::vector<std::vector<long long>> p(3, std::vector<long long>(4, 0));
    for (std::size_t i = 0; i < 2; ++i)
        for (std::size_t j = 0; j < 3; ++j)
            p[i + 1][j + 1] = g[i][j] + p[i][j + 1] + p[i + 1][j] - p[i][j];
    std::cout << p[2][3] - p[0][3] - p[2][1] + p[0][1] << '\n';
}

``

1116215

2. What does this program print? ``

cpp
#include <iostream>

int main() {
    int rows = 10;
    int visits = 0;
    for (int i = 1; i <= rows; i += i & -i) ++visits;
    std::cout << visits << '\n';
}

``

21034

3. After one insert into an empty dynamic segment tree that covers the values 0 to 1000000000, how many nodes are in use, with the root counted?

130311000000001

4. Why does the lesson 12 code write the midpoint as l + (r - l) / 2 instead of (l + r) / 2?

It is faster to compute than (l + r) / 2l + r can overflow an int for bounds near 2000000000, so the midpoint comes out wrongIt rounds the midpoint up instead of downIt keeps the root at index 1 of the pool

5. Which statements about the dynamic segment tree in lesson 12 are true?

Pick every answer that is true.

Node 0 is the null node, and a child link of 0 means there is no child.The class stores raw pointers to nodes, so references stay valid when the pool grows.count returns 0 for a range whose node was never created.A value outside the range is rejected with an error message.The class never removes a node when its count falls back to 0.

Dynamic trees and 2D sums