09 - Advanced vector and array, algorithm

🔨 🔥 Assignment 🔥 🔨

Create a new project in the way explained in the first instruction.

Two dimensional vectors

There are multiple ways to create multidimensional array. One of them is to use nested std::vector. To create a two-dimensional array (e.g. for storing the board in a checkers game) a vector of vectors can be used. Consider the example below:

const int number_of_rows = 5;
const int number_of_cols = 5;

std::vector<std::vector<int>> two_dimensional_vector;

for (int i = 0; i < number_of_rows; i++) {
   std::vector<int> row;
   for (int j = 0; j < number_of_cols; j++) {
       row.emplace_back(10 * i + j);
   }

   two_dimensional_vector.emplace_back(row);
}

std::cout << "Row 2, column 3: " << two_dimensional_vector[2][3] << std::endl;

🔨 🔥 Assignment 🔥 🔨

1. Copy the code generating two dimensional array (using a std::vector of std::vectors). Add a function that prints the 2d array separated by a tabulator (\t) sign for columns and a new line for rows. The result should be:

0       1       2       3       4
10      11      12      13      14
20      21      22      23      24
30      31      32      33      34
40      41      42      43      44

2. Create a two dimensional array (using std::vector type) of size 3x3 and fill it with random values (0-10). Write a function that multiplies elements in the array by 2 (in place).

algorithm module

The algorithm header file defines a set of utility functions designed mainly for collections. In order to use it include appropriate header:

#include <algorithm>

Interesting functions from algorithm header:

• std::min_element - returns an iterator to smallest value in range
• std::max_element - returns an iterator to largest value in range
• std::fill - fills provided range of collection with value
• std::all_of - returns true if all the elements in range fulfil the provided condition, otherwise returns false
• std::any_of - returns true if any of the elements in range fulfil the provided condition, otherwise returns false
• std::none_of - returns true if none of the elements in range fulfil the provided condition, otherwise returns false
• std::find_if - returns iterator to the first element in range that fulfils the predicate
• std::count_if - returns the number of elements in range that fulfils the predicate
• std::sort - sorts the elements in the range

For more functions see: http://www.cplusplus.com/reference/algorithm/

🔨 🔥 Assignment 🔥 🔨

1. Create a structure ExchangeRate containing fields:

   • date - std:string,
   • rate - float.

2. Read the USD vs. PLN exchange rate data from file: USDvsPLN.csv. Store it in a std::vector of ExchangeRate structures.

3. Using std::min_element find a date when USD vs. PLN exchange rate was the smallest. Print the date and corresponding rate.

4. Using std::max_element find a date when USD vs. PLN exchange rate was the largest. Print the date and corresponding rate.

5. Check if all the exchange rates stored in file are from year 2020 (std::all_of).

6. Find a date when the exchange rate went over 4.22 for the first time (std::find_if).

7. Count for how many days the exchange rate was over 4.22 (std::count_if).

Final assignments 🔥 🔨

Exercise 1 - Tic-tac-toe game

Write a simple Tic-tac-toe game in the following steps:

• create a variable that will let you store the game state (e.g. std::vector<std::vector<char>>)

• write a function that will print the current game state (board) in a readable way

• write a function that will let a player insert x or o in a specified location (ask the user for coordinates of the field)

• write a function that checks if one of the players has won

• add game logic (turns) - use previously created functions, ask the players alternately to input their moves, print current board state, check for winner

Exercise 2

This year, due to a lack of a snow, Santa Claus forgot to prepare gifts and now asks you to help. Write a program, that will help him plan a flight. Santa will fly from north-west and would like to visit children in specific order. Read children’s names and coordinates of their houses (integer numbers, x rises in the east direction, y rises in the north direction) and print in an order form the one living the most north-west to the one living the most south-east. Use a proper structure and a sort function with a proper comparator.

Example input:

Kacper 1 1
Melchior -4 1
Baltazar -3 4
Maria 3 1

Example output:

Baltazar
Melchior
Kacper
Maria

Authors: Michał Fularz, Piotr Kaczmarek, Dominik Pieczyński, Tomasz Mańkowski, Jakub Tomczyński