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Game Homework Solution In C++
Game of Nim
It is an intro to programming C++. The code should be written that way
Sample output 1:
Welcome to the game of Nim.
There are 16 marbles in the pile.
Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ
Computer plays:
The computer takes 3 marbles.
There are 13 marbles in the pile.
Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ
Your play .. you may take 1 to 6 marbles. You take: I will move 6 marbles↵
Invalid! Please try again...
Your play .. you may take 1 to 6 marbles. You take: six marbles↵
Invalid! Please try again...
Your play .. you may take 1 to 6 marbles. You take: 6 marbles ok?↵
You will take 6 marbles.
There are 7 marbles in the pile.
Φ Φ Φ Φ Φ Φ Φ
Computer plays:
The computer takes 3 marbles.
There are 4 marbles in the pile.
Φ Φ Φ Φ
Your play .. you may take 1 to 2 marbles. You take: 4↵
Ooops, you picked too many or not enough. Please try again...
Your play .. you may take 1 to 2 marbles.
You take: three↵
Invalid! Please try again...
Your play .. you may take 1 to 2 marbles. You take: 3↵
Ooops, you picked too many or not enough. Please try again...
Your play .. you may take 1 to 2 marbles. You take: 2↵
You will take 2 marbles.
There are 2 marbles in the pile.
Φ Φ
Computer plays:
The computer takes 1 marble.
You must take the last marble. You lose!
Sample output 2:
You will play first.
The computer will play smart.
There are 10 marbles in the pile.
Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ
In your play .. you may take 1 to 5 marbles.
You take: 5 marbles and I will see how you move:)↵ You will take 5 marbles.
There are 5 marbles in the pile.
Φ Φ Φ Φ Φ
Computer plays:
The computer takes 2 marbles.
There are 3 marbles in the pile.
Φ Φ Φ
In your play .. you may take 1 to 1 marble. You take: -5↵
Ooops, you picked too many or not enough. Please try again...
In your play .. you may take 1 to 1 marble. You take: 7↵
Ooops, you picked too many or not enough. Please try again...
In your play .. you may take 1 to 1 marble. You take: 1↵
You will take 1 marble.
There are 2 marbles in the pile.
Φ Φ
Computer plays:
The computer takes 1 marble.
You must take the last marble. You lose!
Sample output 3:
The computer will play first.
The computer will not play smart.
There are 15 marbles in the pile.
Φ
Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ
Computer plays:
The computer takes 6 marbles.
There are 9 marbles in the pile.
Φ Φ Φ Φ Φ Φ Φ Φ Φ
Your play .. you may take 1 to 4 marbles. You take: three is my choice↵
Invalid! Please try again...
Your play .. you may take 1 to 4 marbles. You take: 3 is my smart choice↵
You will take 3 marbles.
There are 6 marbles in the pile.
Φ Φ Φ Φ Φ Φ
Computer plays:
The computer takes 2 marbles.
There are 4 marbles in the pile.
Φ Φ
Φ Φ
Your play .. you may take 1 to 2 marbles. You take 1 and I am smart:) ↵
You will take 1 marble.
There are 3 marbles in the pile.
Φ Φ Φ
Computer plays:
The computer takes 1 marble.
There are 2 marbles in the pile.
Φ Φ
In your play, you may take 1 to 1 marble. You take: 1 and I will win the game:) ↵ You will take 1 marble.
The computer must take the last marble. You win!
Solution:
*/
#include < cstdlib>
#include < iostream>
#include < string>
#include < time.h>
using namespace std;
const int PILE_MAX = 50;
const int PILE_MIN = 10;
const char MARBLE = static_cast(232); // "Φ";
/*
* It represents the legal move when it is the computer's turn to play
* computer's legal move is under either smart-move or
* non-smart-move depending on the parameter named smart
*@param pile int&: the pile size before its turn and after its turn,
call by reference
*@param smart bool: representing the computer takes smart move (if true)
or non-smart move (if false)
*@return: void function
*/
void computer_play(int& pile, bool smart) {
int computer = 0;
// Display the number of marbles on current pile
cout << "There are " << pile << " marbles in the pile." << endl;
for ( int i = 0; i < pile; i++ ) {
cout << " " << MARBLE << endl;
}
if ( smart ) {
// For smart-move mode
// Check whether pile is equal to 2's power - 1
if ( pile == 1 || pile == 3 || pile == 7 || pile == 15 || pile == 31 ) {
// make a random move taking at least one but at most half of the marbles
computer = rand() % ( pile / 2 ) + 1;
} else {
// otherwise, take off enough marbles to make the size of the remaining pile
// a power of two minus one
if ( pile > 31 ) {
computer = pile - 31;
} else if ( pile > 15 ) {
computer = pile - 15;
} else if ( pile > 7 ) {
computer = pile - 7;
} else if ( pile > 3 ) {
computer = pile - 3;
} else if ( pile > 1 ) {
computer = pile - 1;
}
}
} else {
// For non-smart-move mode, make a random move taking at least one but at most half of the marbles
computer = rand() % ( pile / 2 ) + 1;
}
// Print how many marbles do the computer player takes
cout << "Computer plays:" << endl;
cout << "The computer takes " << computer << " marbles." << endl;
// Update the number of marbles in the pile
pile -= computer;
}
/*
* It represents the legal move when it is the user's turn to play the game
* (it should repeatedly ask the user to enter how many marbles to take
* until the user makes a legal move.)
*@param pile int&: the pile size before user's turn and after user's turn,
call by reference
*@return: void function
*/
void player_play(int& pile) {
string line;
bool isValid;
int max_player;
int player;
// Display the number of marbles on current pile
cout << "There are " << pile << " marbles in the pile." << endl;
for ( int i = 0; i < pile; i++ ) {
cout << " " << MARBLE << endl;
}
do {
// Calculate the maximum allowable marbles to be taken by the user player
max_player = pile / 2;
// Prompt to the user player to show what is the available range
cout << "Your play .. you may take 1 to " << max_player << " marbles." << endl;
cout << "You take: ";
getline( cin, line );
try {
// Use the stoi function to convert the input string line into integer
player = atoi( line.c_str() );
// If the user player takes too many or not enough marble
if ( player < 1 || player > max_player ) {
// print the error message, and request the user to input again
cout << "Ooops, you picked too many or not enough." << endl;
cout << "Please try again..." << endl;
isValid = false;
} else {
// If the user input is valid, print how many marbles do the user player takes
cout << "You will take " << player << " marbles." << endl;
isValid = true;
}
} catch (invalid_argument ex) {
// If the user input is not a valid number, the stoi function will generate exception
// and catch the exception with the exception handler to print the error message
cout << "Invalid! Please try again..." << endl;
isValid = false;
}
} while (isValid == false);
// Update the number of marbles in the pile
pile -= player;
}
int main(int argc, char** argv) {
int pile; /* Randomize the total number of marbles in the pile. */
bool first; /* Randomize which player (the computer or the user) takes the first turn. */
/* 1 - User player first; 0 - Computer player first */
bool smart; /* Randomize whether the computer takes either “smart†move or “non-smart†move. */
// Print out the follow information at the beginning of the game
cout << "*****************************************************" << endl;
cout << "* The game of Nim *" << endl;
cout << "* Players alternate taking at least one but at *" << endl;
cout << "* most half of the marbles in the pile. *" << endl;
cout << "* The player who takes the last marble loses. *" << endl;
cout << "* It is written by XXX *" << endl;
cout << "* I hope you beat the computer:) *" << endl;
cout << "* No matter what, have a great day. *" << endl;
cout << "*****************************************************" << endl;
// Using time function to randomize the seed
srand ((unsigned int)time(NULL));
// Generate a random integer between PILE_MIN and PILE_MAX to denote the initial pile size
pile = rand() % ( PILE_MAX - PILE_MIN + 1 ) + PILE_MIN;
// Generate 0 or 1 randomly to decide which player (the computer or the user) takes the first turn
first = rand() % 2;
// Generate 0 or 1 randomly to decide if the computer takes either “smart†move or “non-smart†move
smart = rand() % 2;
// Based on the random variable, first, print out which player will go first
if ( first ) {
cout << "You will play first." << endl;
} else {
cout << "The computer will play first." << endl;
}
// Based on the random variable, smart, print out what strategy will the computer player use
if ( smart ) {
cout << "The computer will play smart." << endl;
} else {
cout << "The computer will not play smart." << endl;
}
cout << endl;
// If the user player does not go first
if ( first == false ) {
/* Computer Round */
computer_play( pile, smart );
// Since the smallest number of marbles is 10, therefore after the first round will not
// have only 1 marble left, so that no need to handle who will lose the game
cout << endl;
}
do {
/* Player Round */
player_play( pile );
// If there is only one marble left after the user player's round
if ( pile == 1 ) {
// Print the computer player will lose the game
cout << "Computer must take the last marble. You win!" << endl;
break;
}
cout << endl;
/* Computer Round */
computer_play( pile, smart );
// If there is only one marble left after the computer player's round
if ( pile == 1 ) {
// Print the user player will lose the game
cout << "You must take the last marble. You lose!" << endl;
break;
}
cout << endl;
} while ( pile > 0 );
return 0;
}