数组索引超出范围认为存在特定线

Question

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 100 at ham.main(ham.java:34)

line 34 on my console says if (h[c] == 1)

i wrote a code to generate hamming code..i am getting the javaindexoutbounds exception..i even gave absurdly large array sizes to counter tht..still not working! The array is outbounds even thou there plenty of space for the array

the line 27 might be a mistake...checking for c

 import java.util.*;

public class ham {
public static void main(String ar[]) {
    Scanner s = new Scanner(System.in);
    System.out.println("input no. of bits");
    int n = s.nextInt();
    int a[] = new int[100]; // user's input
    int h[] = new int[100]; // hamming code array
    System.out.println("i/p the data");
    int i = 1, j = 1, pb = 1;
    for (i = 1; i < n + 1; i++)
        a[i] = s.nextInt();
    i = 1;

    while (i < n + 1) {
        if (j == pb) // if the index is a parity bit leave it
        {
            j++;
            pb = pb * 2;
        } else {
            h[j] = a[i];
            j++;
            i++;
        } // else copy the data bits from a[] to h[]
    }

    int c = 0, counter = 0; // to fill the parity bits(k)
    for (int k = 1; k <= j; k = 2 * k) {
        c = k;
        while (c <= j) // 'j' is position of the last data bit in h[]
        {
            for (c = k; c < (c + k); c++) {
                if (h[c] == 1)   // this is line 34
                    counter++;
            }
            c = c + k + 1;
        }
        if (counter % 2 == 0)
            h[k] = 0;
        else
            h[k] = 1;
    }
    System.out.println("hamming code is");
    for (i = 1; i <= j; i++)
        System.out.print(h[i] + " ");
}

}

Answer 1

The if (h[c] == 1) test is causing the exception.

Your h array has a fixed size of 100 , but the maximum value of c seems to depend on the user's input, n . You will need to figure out how to dynamically determine your array sizes, depending on the user input.