掷2个六面骰子1000次，意想不到的结果

Question

当模拟掷骰子 2 次 1000 次并显示结果时，它会不断返回意外值。我的程序是：

import java.util.*;
public class Prob1 {
private int sides; //Amount of sides on die
private int sumOfRolls; 
private int[] arr; //Array that holds the count of each sum of the rolls
private int count; //Temporarily holds value of sum of rolls before passing to array
public Prob1() { //Default constructor, sets sides to 6
sides = 6;
sumOfRolls = 0;
count =0;
arr = new int[(sides*2)+1];
}
public void roll() { //Method that rolls the 2 dice
for(int i=0;i<1000;i++) { //Repeats 1000 times
int roll1 = (int) (Math.random()*sides)+1; //Rolls 1 die
int roll2 = (int) (Math.random()*sides)+1; //Rolls other die
sumOfRolls = roll1+roll2; //Sums both rolls
for(int j=2;j<(sides*2)+1;j++) { //Goes through all the possible values of sums of roll
if(sumOfRolls==j) { //Checks if sum of rolls is equal to the value presented by the for loop
count++; //Adds 1 to count of value of sum of roll
arr[j]=count; //Adds that value to array
}
}
}
System.out.println("Roll: " + sides + "-sided dice"); //Displays what kind of dice
}
public void frequency() { //Frequency table
System.out.println("nnnRoll Total  Frequency");
System.out.println("---------------------");
for(int i=2; i<(sides*2)+1; i++) { //Displays each value of array
System.out.print(i + "           " + arr[i] + "n");
}
}

}

当同时调用滚动和频率方法时，结果如下：

Roll: 6-sided dice

Roll Total  Frequency
---------------------
2           952
3           995
4           976
5           989
6           991
7           999
8           1000
9           998
10           992
11           994
12           997

这是错误的，因为每个值的总和超过 1000，即两个骰子掷出的次数。有什么解决方法吗？

Answer 1

问题是您在每次滚动后都没有重置计数变量

消除count++，只做arr[j]++.

编辑

如评论中所述，循环是不必要的，因为您可以只做arr[sumOfRolls]++。