在 x 和 y 之间生成总和为 m 的随机数

Question

我想生成 n 个随机数，其总和应为 m，并且这些数应始终在 x 和 y 之间。

例如：- 如果我说我需要 20 个不，介于 3 和 9 之间，其总和应该是 100。

我想指定 no 的总和和所需数量，以及应该生成随机 no 的限制，它应该给我指定数量的随机 no。下面是我的代码，它生成的 no 大于 2，但我无法设置最大限制。此外，出来的总和和没有的总和。它生成的不等于指定的总和。我完全糊涂了请帮帮我。

TextView textView,randomTotaltxt;
int count0 = 0;
int count1 = 0;
int targetSum = 100;
int numberofDraws = 20;

    textView = (TextView) findViewById(R.id.textview);
    randomTotaltxt = (TextView) findViewById(R.id.randomTptalText);

    Random r = new Random();
    ArrayList<Integer> load = new ArrayList<>();

    //random no
    int sum = 0;
    for (int i=0; i<numberofDraws;i++){
        int next = r.nextInt(targetSum)+1;
        Log.d("No",""+next);
        load.add(next);
        sum += next;
    }

    //scale it
    double scale = 1d*targetSum/sum;
    sum=0;
    for (int i=0; i<numberofDraws;i++){
        load.set(i, (int)(load.get(i)*scale));
        sum += load.get(i);
    }

   while (load.contains(0)|| load.contains(1)){
       for (int i=0; i<load.size();i++) {
           if (load.get(i).equals(0)) {
               load.set(i, load.get(i) + 2);
               count0++;
               sum = sum+1;
           }
           if (load.get(i).equals(1)) {
               load.set(i, load.get(i) + 2);
               sum += load.get(i);
               count1++;
              sum = sum+1;
           }
       }
   }

    // take rounding
    while (sum++ <targetSum){
        int i = r.nextInt(numberofDraws);
        load.set(i, load.get(i) + 1);
    }

    textView.setText(""+load);
    randomTotaltxt.setText(""+(sum-1));

Answer 1

这可能不是最佳解决方案，但可以根据需要完成您的工作。

int targetSum = 100;
int numberOfDraws = 20;
int uppr=0;
int countt =0;
ArrayList<Integer> load = new ArrayList<>();
Random random;
TextView textView1,randomTotaltxt1;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    textView1 = (TextView) findViewById(R.id.textview1);
    randomTotaltxt1 = (TextView) findViewById(R.id.randomTptalText1);

    random = new Random();

    //random no
    int sum = 0;
    for (int i=0; i<numberOfDraws;i++){
        int next = random.nextInt(targetSum)+1;
        load.add(next);
        sum += next;
    }

    //scale it
    double scale = 1d*targetSum/sum;
    sum=0;
    for (int i=0; i<numberOfDraws;i++){
        load.set(i, (int)(load.get(i)*scale));
        sum += load.get(i);
    }

    // take rounding
    while (sum++ <targetSum){
        int i = random.nextInt(numberOfDraws);
        load.set(i, load.get(i) + 1);
        Log.d("TAG",""+load);
    }

    checkForUpperRange();
}

public void checkForUpperRange(){
    for (int i=0; i<numberOfDraws;i++){
        int n = load.get(i);

        if (n > 9){
            load.set(i, 9);
            uppr = n - 9;   // getting the required no.
            adjustUpper();
            break;
        }

        checkForLowerRange();
    }
}

private void adjustUpper() {
    for (int j=0; j<numberOfDraws;j++){
        if (load.get(j) > 2){
            load.set(j, load.get(j)+uppr);    // uppr is added
            checkForUpperRange();
            break;
        }
    }
}

public void checkForLowerRange(){
    for (int i=0; i<numberOfDraws;i++){
        int n = load.get(i);

        if (n == 0){
            load.set(i, load.get(i)+3); // 3 is added in sum
            adjust0();
            break;
        }

        if (n == 1){
            load.set(i, load.get(i)+2); // 2 is added in sum
            adjust1();
            break;
        }

        if (n == 2){
            load.set(i, load.get(i)+1); // 1 is added in sum
            adjust2();
            break;
        }

        getCount();
    }
}

public void getCount(){
    countt = 0;
    for (int k=0; k<numberOfDraws;k++){
        countt = countt+ load.get(k);
        showResult();
    }
}

public void showResult(){
    textView1.setText(""+load);
    randomTotaltxt1.setText(""+countt);
}

public void adjust0(){
    for (int j=0; j<numberOfDraws;j++){
        if (load.get(j) > 3){
            load.set(j, load.get(j)-3);    // 3 is subtracted
            checkForLowerRange();
            break;
        }
    }
}

public void adjust1(){
    for (int j=0; j<numberOfDraws;j++){
        if (load.get(j) > 3){
            load.set(j, load.get(j)-2);    // 2 is subtracted
            checkForLowerRange();
            break;
        }
    }
}

public void adjust2(){
    for (int j=0; j<numberOfDraws;j++){
        if (load.get(j) > 3){
            load.set(j, load.get(j)-1);    // 1 is subtracted
            checkForLowerRange();
            break;
        }
    }
}