c++ - 随机整数/出现次数 (C++) 问题

Question

我目前已经在一个 C++ 问题上停留了大约一个半小时。这是问题:

编写一个程序，生成 0 到 9 之间的一百个随机整数，并显示每个数字的计数。 (提示:使用 rand()% 10 生成 0 到 9 之间的随机整数。使用十个整数的数组，说计数，以存储 O、l 的数量的计数。 .., 9.)

这就是我目前所拥有的。我想我已经很接近了，但是对于每个随机整数的出现(或计数)，我一直得到“0”。任何帮助将不胜感激。

const int SIZE = 100;

int main()
{
int integers[SIZE];
int index;
int zero = 0;
int one = 0;
int two = 0;
int three = 0;
int four = 0;
int five = 0;
int six = 0;
int seven = 0;
int eight = 0;
int nine = 0;

cout << "The following 100 integers are random:" << endl;
cout << endl;

srand(time(0));

for (index = 0; index < SIZE; index++)
{
    integers[SIZE] = rand() % 10;
    cout << integers[SIZE] << " ";
}

cout << endl;

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 0)
    {
        zero += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 1)
    {
        one += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 2)
    {
        two += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 3)
    {
        three += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 4)
    {
        four += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 5)
    {
        five += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 6)
    {
        six += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 7)
    {
        seven += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 8)
    {
        eight += 1;
    }
}

for (index = 0; index < SIZE; index++)
{
    if (integers[index] == 9)
    {
        nine += 1;
    }
}

cout << "The number of zeros in the random list are " << zero << endl;
cout << "The number of ones in the random list are " << one << endl;
cout << "The number of twos in the random list are " << two << endl;
cout << "The number of threes in the random list are " << three << endl;
cout << "The number of fours in the random list are " << four << endl;
cout << "The number of fives in the random list are " << five << endl;
cout << "The number of sixes in the random list are " << six << endl;
cout << "The number of sevens in the random list are " << seven << endl;
cout << "The number of eights in the random list are " << eight << endl;
cout << "The number of nines in the random list are " << nine << endl;

getch();

return 0;

}

Answer 1

您有未定义的行为，因为您使用 SIZE 而不是 index 作为数组的索引:

for (index = 0; index < SIZE; index++)
{
    integers[SIZE] = rand() % 10;
    cout << integers[SIZE] << " ";
}

这将访问数组边界之外(因为范围是从 0 到 SIZE-1)。在循环体内，将 SIZE 更改为 index。

但是，我认为它会帮助您重新阅读您的问题陈述。具体来说:

Use an array of ten integers, say counts, to store the counts for the number of 0s, 1s, ... , 9s

您改为使用数组来存储您的随机数。这根本没有必要。您不需要跟踪生成的数字。您只需将适当的计数加 1，然后就可以简单地丢弃随机数。

你应该简单地有一个名为 counts 的数组，其中 counts[0] 存储到目前为止 0 的数量， counts[1] 存储1的个数，等等。那么你就不需要这些可怕的变量了，叫做zero, one、二等。如果您发现自己定义了这样的变量名(其中的数字越来越多)，那么您可能应该改用数组。