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/*In the game of craps, a “Pass Line” bet proceeds as follows. The first roll of the
two, six-sided dice in a craps round is called the “come out roll.” The bet immediately
wins when the come out roll is 7 or 11, and loses when the come out roll
is 2, 3, or 12. If 4, 5, 6, 8, 9, or 10 is rolled on the come out roll, that number
becomes “the point.” The player keeps rolling the dice until either 7 or the point
is rolled. If the point is rolled first, then the player wins the bet. If the player rolls
a 7 first, then the player loses.
Write a program that plays craps using those rules so that it simulates a game
without human input. Instead of asking for a wager, the program should
calculate whether the player would win or lose. Create a function that simulates
rolling the two dice and returns the sum. Add a loop so that the program plays
10,000 games. Add counters that count how many times the player wins, and
how many times the player loses. At the end of the 10,000 games, compute the
probability of winning, as Wins / (Wins + Losses), and output this value. Over
the long run, who is going to win more games of craps, you or the house?*/
#include <iostream>
#include <cstdlib>
using std::cout;
using std::endl;
using std::cin;
using std::ios;
void setPrecision();
void setRandomSeed();
int diceRoll();
int main()
{
int playerWin = 0, houseWin = 0, thePoint = 0, secondRoll = 0, dice = 0;
double probabilityOfWinning = 0;
setPrecision(); //fix decimal outputs to 2 places
setRandomSeed(); //change seed number for rand() to allow testing with different outputs
for(int a = 0; a <= 10000; a++)
{
thePoint = 0;
dice = diceRoll();
if(dice == 7 || dice == 11)
{
playerWin++;
continue;
}
else if(dice == 2 || dice == 3 || dice == 12)
{
houseWin++;
continue;
}
else
{
thePoint == dice;
do
{
secondRoll = diceRoll(); //roll dice again
if(secondRoll == thePoint)
{
playerWin++;
break;
}
else if(secondRoll == 7)
{
houseWin++;
break;
}
}
while(secondRoll != thePoint || secondRoll != 7); //keep rolling until the Point or a 7 is rolled
}
}
cout << "Player wins " << playerWin << " times." << endl;
cout << "House wins " << houseWin << " times." << endl;
probabilityOfWinning = (static_cast<double>(playerWin) / (playerWin + houseWin)) * 100; //cast needed to get round integer division
cout << "Probability of winning is " << probabilityOfWinning << "%" << endl;
return 0;
}
//ensure all floating point number are rounded to 2 decimal places
void setPrecision()
{
cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(2);
}
//set a different seed for rand() to allow testing of program with different outputs
void setRandomSeed()
{
int randSeed;
cout << "Enter a seed: ";
cin >> randSeed;
srand(randSeed);
}
//simulate rolling of two dice
int diceRoll()
{
int firstDice = 0, secondDice = 0;
do
{
firstDice = rand() % 7; //modulo 7 so that maximum value is 6
}
while(firstDice == 0); //dice roll can't be a 0
do
{
secondDice = rand() % 7; //modulo 7 so that maximum value is 6
}
while(secondDice == 0); //dice roll can't be a 0
return firstDice + secondDice;
}
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