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1. This program prints a checkerboard. What does the second line of output look like? ``

cpp
#include <iostream>
#include <string>

std::string checkerboard(int rows, int cols, char dark, char light) {
    std::string picture;
    for (int row = 0; row < rows; ++row) {
        for (int col = 0; col < cols; ++col) {
            picture += ((row + col) % 2 == 0) ? dark : light;
        }
        picture += '\n';
    }
    return picture;
}

int main() {
    std::cout << checkerboard(3, 3, '*', '-');
}

``

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2. What does this program print? ``

cpp
#include <iostream>

int count_dark(int rows, int cols) {
    int dark = 0;
    for (int row = 0; row < rows; ++row) {
        for (int col = 0; col < cols; ++col) {
            if ((row + col) % 2 == 0) {
                ++dark;
            }
        }
    }
    return dark;
}

int main() {
    std::cout << count_dark(4, 3) << '\n';
}

``

5674

3. This checkerboard test is meant to alternate the cells, but it does not. Which part is the bug? ``

cpp
if (row + col % 2 == 0) {
    std::cout << '#';
} else {
    std::cout << '.';
}

`



The first row of a 3 by 3 grid is

#.#`, but the next two rows are all dots.

It does not compile, because % cannot be used next to + in one expressionThe else branch should print #, not .The loops should use <= so the last row is printed% binds before +, so the test adds row to the remainder of col divided by 2, and only row 0 can match

4. Why does the checkerboard use (row + col) % 2 and not row % 2?

row % 2 is slower to compute, so the sum is used for speedrow % 2 is only 0 or 1, so the picture would have only two cellsrow % 2 alone gives horizontal stripes, because every cell in a row gets the same answerrow % 2 alone gives a checkerboard twice the size

5. The grid art draws a grid with 3 cells across. How many characters wide is each line of the picture?

1312149

Grids