[CarltonBirch]

I tried to run program, after first correct output (number 32) , I get this:

Exception in thread "main" 32
java.lang.IndexOutOfBoundsException: Index: 6, Size: 6
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at Rad.out(Rad.java:44)
at Rad.main(Rad.java:25)

I think that I attempting to access an index that doesn’t currently exist in the ArrayList.
How to fix this problem in code?

import java.util.*;
public class Rad {
public static ArrayList heap = new ArrayList();
public static Scanner cin = new Scanner(System.in);
public static void main(String[] args)
{
heap.add(0);
int n,x;
n = cin.nextInt();
for (int i = 0;i < n;i++)
{
x = cin.nextInt();
ubaci(x);
}
int m,y;
m = cin.nextInt();
for (int i = 0;i < m;i++) {

y = cin.nextInt();
if (y == 0)
{
if (heap.size() > 1)
{
System.out.println(heap.get(1));
izvadi();
}
else

System.out.println("Nema!");}
else
ubaci(y);
}
System.exit(0);}
public static void ubaci(int x) {
heap.add(x);
int t = heap.size()-1;
while (((t/2)!=0) && heap.get(t)>heap.get(t/2)){
int temp = heap.get(t/2);
heap.set(t/2, heap.get(t));
heap.set(t, temp);
t/=2;
}
}
public static void izvadi() {
heap.set(1, heap.get(heap.size()));
heap.remove(heap.size());
int t = 1, r;
while(true) {
if (t*2+1 < heap.size()) {
if(heap.get(t*2) > heap.get(t*2+1))
r = t*2;
else
r = t*2+1;
} else if(t*2 < heap.size())
r=t*2;
else
break;

if(heap.get(r) > heap.get(t)) {
int temp = heap.get(t);
heap.set(t, heap.get(r));
heap.set(r, temp);
t = r;
} else
break;

}
}}

Input:
5
15 32 4 18 29
12
0 0 50 0 24 97 0 0 0 0 0 0
Print:
32 29 50 97 24 18 15 4 No

When input is 0, output is largest number in heap.If input is some other number,then it is stored in heap.

[ShikhaTan]

Accessing the # element that doesn’t exist because of the size() method. Size() method brings the actual size of the heap.

EX: You add 3(a,b,c) items their positions are the following 0 = a, 1 = b, 2 = C. When you heap.get(heap.size()) you are accessing the element in position 3 which doesn’t exist. You must call

heap.set(1, heap.get(heap.size() - 1));