Mehran Sahami Handout #16
CS 106A October 10, 2007
Examples of Programs Using Random Numbers
Portions of this handout by Eric Roberts
/*
* File: RollDice.java
* -------------------
* This program simulates rolling some number of dice until
* the maximal value on the all the dice is rolled.
*/
import acm.program.*;
import acm.util.*;
public class RollDice extends ConsoleProgram {
/* Number of sides on each die */
private static final int NUM_SIDES = 6;
public void run() {
int numDice = readInt("Number of dice: ");
int maxRoll = numDice * NUM_SIDES;
int numRolls = 0;
while (true) {
int roll = rollDice(numDice);
numRolls++;
if (roll == maxRoll) break;
println("Rolled " + roll);
}
println("Rolled " + maxRoll + " after " + numRolls + " rolls");
}
/* Returns the total of rolling numDice dice */
private int rollDice(int numDice) {
int total = 0;
for (int i = 0; i < numDice; i++) {
total += rgen.nextInt(1, NUM_SIDES);
}
return total;
}
/* Private instance variables */
private RandomGenerator rgen = RandomGenerator.getInstance();
}
