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1. What does this program print? ``

cpp
#include <iostream>
#include <string>

int main() {
    const int n = 3;
    for (int i = 0; i < n; ++i) {
        std::string half(i + 1, '*');
        std::string gap(2 * (n - 1 - i), ' ');
        std::cout << half << gap << half << '\n';
    }
}

``

* * ** ** ******* * ** ** ******* * ** ** ****** * ** ** ******

2. What does this program print? ``

cpp
#include <iostream>
#include <string>

int main() {
    const int rows = 3;
    for (int row = 1; row <= rows; ++row) {
        std::string line(rows - row, ' ');
        line += std::string(2 * row - 1, '*');
        std::cout << line << '\n';
    }
}

``

* *** ***** * *** ***** * *** ***** * *** *****

3. This program is meant to print a stack of rows, but it crashes on the last step. What is the bug? ``

cpp
#include <iostream>
#include <string>

int main() {
    const int n = 4;
    for (int i = 0; i <= n; ++i) {
        std::cout << std::string(2 * (n - 1 - i), ' ')
                  << std::string(i + 1, '*') << '\n';
    }
}

``

The loop runs one extra time with i = n, so the gap count becomes -2 and std::string throws. The loop should use i < nThe gap should be 2 * i, so the shape grows downwardstd::cout needs std::endl at the end of each rowThe stars should be std::string(i, '*'), so row 0 is empty

4. This program is meant to print a triangle of stars: one star on row 1, two on row 2 and three on row 3. What is the bug? ``

cpp
#include <iostream>
#include <string>

int main() {
    const int rows = 3;
    std::string line;
    for (int row = 1; row <= rows; ++row) {
        for (int col = 1; col <= row; ++col) {
            line += '*';
        }
        std::cout << line << '\n';
    }
}

``

The inner loop should run row + 1 timesline is declared outside the row loop, so the stars from earlier rows stay and row 2 prints three starsstd::cout needs std::flush after each rowThe outer loop should use < so that row 3 is not printed

5. True or false: a number pyramid's right half can be made by printing the left half again, the same way the star mirror is made.

True, because a row of digits reads the same forwards and backwardsFalse, because the right half counts back down from i, so it needs its own loop

Rows and mirrors