简体   繁体   中英

Java: Creating a frequency table for integers randomly generated and placed in an array

Thanks everybody! I cleaned up the code to the best of my knowledge and decided to paste the completed code along with a sample output for other students to see and if they choose to use parts of the code.

public class Arrays {
  public static void main(String args[]) {
    //Assigning the array length according to the user's input
    int N = Integer.parseInt(args[0]);
    int randoms[] = new int[N];
    //Filling the array with random integer values
    System.out.println("The numbers generated are: ");
    for (int i=0; i<randoms.length; i++) {
      randoms[i] = (int) (Math.random()*10 + 1);
      System.out.print(randoms[i] + " ");
    }
    double sum = 0.0;
    for (int i=0; i<randoms.length; i++) {
      sum += randoms[i];
    }
    System.out.println("\nThe average of the values is " + (sum/N));
    int freq[] = new int[11];
    for (int i=0; i<randoms.length; i++){
      freq[randoms[i]] += 1; 
    } 
    System.out.println("Number\tFreq");
    for (int i=1; i<freq.length; i++){
      System.out.println(i + "\t" + freq[i]);
    }
  }
}

Sample Output:

> java Arrays 15
The numbers generated are: 
4 8 1 10 6 7 8 4 6 6 3 4 4 5 8 
The average of the values is 5.6
Number  Freq
1       1
2       0
3       1
4       4
5       1
6       3
7       1
8       3
9       0
10      1

As Adrian pointed out you're currently only counting ones. I would be a bit tricky and instead of doing a check on each one, simply using the random integer to select the correct element for increment

for (int i=0; i<randoms.length; i++){
    freq[randoms[i]-1] += 1; 
 } 

Thanks for the help! After looking at the code long enough I realized that in my output i was using

for (int i=0; i<randoms.length; i++){
      System.out.println(randoms[i] + " appeared " + freq[i] + " times");

When I should have used

for (int i=0; i<randoms.length; i++){
      System.out.println(randoms[i] + " appeared " + freq[randoms[i]] + " times");

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM