java - 如何从命令行查找数组中最常重复的数字？

Question

我需要从命令行获取个位数整数并将它们放入一个数组中，然后找到最常见的整数。有时这个程序似乎有效，有时却无效。

public class MostFrequent {
    public static void main(String[] args){
    int num=0;
    int[] freq= new int[9];//intialize array for integers 0-9
    for (int i=0; i<args.length; i++){
      try {
        num = Integer.parseInt(args[i]);
        freq[num]++;//adds to array counter
        }
        catch (NumberFormatException nfe) {
        }
    }
    int max=0,j;
    for (j=0; j<10; j++){
      while(freq[j]>max){
        max=freq[j];
      }
    }
    System.out.println("The digit that appears most frequently is " + freq[j]);
  }
}

感谢大家的帮助，这就是最终对我有用的方法，并且感谢任何提到使数组更加动态的人，这也很有帮助。 这是我完成的代码:

    public class MostFrequent {
public static void main(String[] args){
int num=0;
int[] freq= new int[args.length];//intialize array for integers 0-9
for (int i=0; i<args.length; i++){
  try {
    num = Integer.parseInt(args[i]);
    freq[num]++;//adds to array counter
    }
    catch (NumberFormatException nfe) {
    }
}
int max=0,j;
for (j=1; j<args.length; j++){
  while(freq[j]>freq[max]){//compares a max array val to the previous val
    max=j;
  }
}
System.out.println("The digit that appears most frequently is " + max);

}}

Answer 1

你的第二个循环中的逻辑有缺陷。另外，您还没有为数组中的所有数字分配空间，为此您需要一个 int[10] 。解决这个问题的一种方法是这样的:

int[] freq = new int[10];//intialize array for integers 0-9

...

int maxindex = 0;
for (int j = 1; j < 10; j++){
    if (freq[j] > freq[maxIndex]) {
        maxIndex = j;
    }
}
System.out.println("The digit that appears most frequently is " + j + ", that appears " + freq[j] + " times.";