43 n 个筛子 的点数

package question43;

public class DicsProbability {  
    /*
     * 把n个骰子仍在地上，所有骰子朝上一面的点数之和为s,输入n,打印出s的所有可能出现的概率
     */  
    public static void printProbability(int number) {  
        if (number < 1)  
            return;  
        int g_maxValue = 6;  
        int[][] probabilities = new int[2][];  
        probabilities[0] = new int[g_maxValue * number + 1];  
        probabilities[1] = new int[g_maxValue * number + 1];  
        int flag = 0;  
        for (int i = 1; i <= g_maxValue; i++)  
            probabilities[0][i] = 1;  
        for (int k = 2; k <= number; ++k) {  
            for (int i = 0; i < k; ++i)  
                probabilities[1 - flag][i] = 0;  
            for (int i = k; i <= g_maxValue * k; ++i) {  
                probabilities[1 - flag][i] = 0;  
                for (int j = 1; j <= i && j <= g_maxValue; ++j)  
                    probabilities[1 - flag][i] += probabilities[flag][i - j];  
            }  
            flag = 1 - flag;  
        }  
        double total = Math.pow(g_maxValue, number);  
        for (int i = number; i <= g_maxValue * number; i++) {  
            double ratio = (double) probabilities[flag][i] / total;  
            System.out.println(i);  
            System.out.println(ratio);  
        }  
    }  
    public static void main(String[] args) {
        printProbability(1);
        printProbability(2);
    }
}