Exercise 7

Added Exercise 7 to Repository

Informatik_I/Exercise_7/Task_3/README.org

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+#+title: Task 3: [Hidden tests] Trapezoid printing
+
+#+author: JirR02
+* Task
+:PROPERTIES:
+:CUSTOM_ID: task
+:END:
+In this exercise, you are going to print trapezoids. A trapezoid is
+defined by the width of its base and its height. A trapezoid can also
+either be rightsideup or upsidedown.
+
+*Note*: It is *mandatory* to use *recursive implementation* for this
+task.
+
+** Examples
+:PROPERTIES:
+:CUSTOM_ID: examples
+:END:
+*** Rightsideup trapezoid with height and width \(3\) (aka a triangle)
+:PROPERTIES:
+:CUSTOM_ID: rightsideup-trapezoid-with-height-and-width-3-aka-a-triangle
+:END:
+#+begin_src sh
+  0
+ 0 0
+0 0 0
+#+end_src
+
+Upsidedown trapezoid with height and width \(3\) (aka an upsidedown
+triangle)
+
+#+begin_src sh
+0 0 0
+ 0 0
+  0
+#+end_src
+
+*** Rightsideup trapezoid with base width 5 and height 2
+:PROPERTIES:
+:CUSTOM_ID: rightsideup-trapezoid-with-base-width-5-and-height-2
+:END:
+#+begin_src sh
+ 0 0 0 0
+0 0 0 0 0
+#+end_src
+
+** Subtask 1: print_trapezoid
+:PROPERTIES:
+:CUSTOM_ID: subtask-1-print_trapezoid
+:END:
+Implement the function print_trapezoid. The function takes three
+arguments:
+
+- =int base_width=: The width of the trapezoid's base
+- =int height=: The height of the trapezoid
+- =int offset_left=: The number of spaces between the left edge of the
+  trapezoid's base and the left edge of the console.
+- =bool upsidedown=: Boolean indicating whether or not the trapezoid is
+  upsidedown or rightsideup.
+
+When called, the function should print the specified trapezoid to the
+console.
+
+** Subtask 2: print_diamond:
+:PROPERTIES:
+:CUSTOM_ID: subtask-2-print_diamond
+:END:
+Implement the function =print_diamond=.
+
+The function prints a diamond with a given center width to the console.
+A diamond is a rightsideup trapezoid on top of an upsidedown trapezoid.
+
+For example, a diamond of width \(5\) looks as follows:
+
+#+begin_src sh
+    0
+   0 0
+  0 0 0
+ 0 0 0 0
+0 0 0 0 0
+ 0 0 0 0
+  0 0 0
+   0 0
+    0
+#+end_src
+
+** Subtask 3: print_hourglass:
+:PROPERTIES:
+:CUSTOM_ID: subtask-3-print_hourglass
+:END:
+Implement the function =print_hourglass=.
+
+The function prints an hourglass with a given base width to the console.
+A hourglass is an upsidedown trapezoid on top of a rightsideup
+trapezoid.
+
+For example, an hourglass of width \(5\) looks as follows:
+
+#+begin_src sh
+0 0 0 0 0
+ 0 0 0 0
+  0 0 0
+   0 0
+    0
+   0 0
+  0 0 0
+ 0 0 0 0
+0 0 0 0 0
+#+end_src
+
+*Note*: The autograder will only accept output that exactly matches the
+expected result. Therefore, do not output anything with std::cout beyond
+what is strictly required (i.e., ” ","=0=", and =std::endl= /"=n=“). For
+debugging messages, use =std::cerr= as in:
+
+#+begin_src cpp
+std::cerr << "This is a test message." << std::endl;
+#+end_src
+
+Those will be ignored by the autograder.
+
+* Hidden test cases
+:PROPERTIES:
+:CUSTOM_ID: hidden-test-cases
+:END:
+This exercise has some hidden test cases. You will see whether these
+tests passed or failed, but you will not see the test input or the
+expected output.
+
+** Persistent input
+:PROPERTIES:
+:CUSTOM_ID: persistent-input
+:END:
+To help you in testing your code, you can enter your custom test input
+in =input.txt=. When running the program, you can let CodeExpert read
+the input from the file.
+
+Write some program input in input.txt. Run the program as usual. Type f
+(no spaces) in the terminal window and press Enter. The program will use
+the contents of input.txt as input. Using this feature is entirely
+optional and does not affect your score.
+
+* Solution
+:PROPERTIES:
+:CUSTOM_ID: solution
+:END:
+#+begin_src cpp
+#include <assert.h>
+
+#include <iostream>
+
+#include "solution.h"
+
+void print_row(int n_bricks, int offset_left) {
+  // print spaces for offset
+  for (int i = 0; i < offset_left; ++i) {
+    std::cout << " ";
+  }
+
+  // print bricks
+  for (int i = 0; i < n_bricks; ++i) {
+    if (i != 0) {
+      std::cout << " ";
+    }
+    std::cout << "0";
+  }
+  std::cout << std::endl;
+}
+
+void print_trapezoid(int base_width, int height, int offset_left,
+                     bool upsidedown) {
+  assert(base_width >= height);
+
+  if (upsidedown == true) {
+    if (height == 0)
+    return;
+
+    print_row(base_width, offset_left);
+    print_trapezoid(base_width - 1, height - 1, offset_left + 1, upsidedown);
+  } else if (upsidedown == false) {
+    if (height == 0)
+    return;
+
+    print_row(base_width - height + 1, offset_left + height - 1);
+    print_trapezoid(base_width, height - 1, offset_left, upsidedown);
+}
+}
+
+void print_diamond(int center_width) {
+  print_trapezoid(center_width, center_width, 0, false);
+  print_trapezoid(center_width - 1, center_width - 1, 0, true);
+}
+
+void print_hourglass(int base_width) {
+  print_trapezoid(base_width, base_width, 0, true);
+  print_trapezoid(base_width, base_width - 1, 0, false);
+#+end_src