如何将一个数组最佳地划分为两个子数组，以使两个元素的总和相同，否则会出现错误？

public class Problem1 {public static void main(String[] args) throws IOException{    Scanner scanner=new Scanner(System.in);    ArrayList<Integer> array=new ArrayList<Integer>();    int cases;    System.out.println("Enter the test cases");    cases=scanner.nextInt();    for(int i=0;i<cases;i++){        int size;        size=scanner.nextInt();        System.out.println("Enter the Initial array size : ");        for(int j=0;j<size;j++){ System.out.println("Enter elements in the array"); int element; element=scanner.nextInt(); array.add(element);        }    }    if(validate(array)){System.out.println("Array can be Partitioned");}  else{     System.out.println("Error");}}public static boolean validate(ArrayList<Integer> array){    boolean flag=false;    Collections.sort(array);    System.out.println(array);    int index=array.size();    ArrayList<Integer> sub1=new ArrayList<Integer>();    ArrayList<Integer> sub2=new ArrayList<Integer>();    sub1.add(array.get(index-1));    array.remove(index-1);    index=array.size();    sub2.add(array.get(index-1));    array.remove(index-1);    while(!array.isEmpty()){    if(compareSum(sub1,sub2)){        index=array.size();        sub2.add(array.get(index-1));        array.remove(index-1);    }    else{        index=array.size();        sub1.add(array.get(index-1));        array.remove(index-1);    }       }    if(sumOfArray(sub1).equals(sumOfArray(sub2)))        flag=true;    else        flag=false;    return flag;}public static Integer sumOfArray(ArrayList<Integer> array){    Iterator<Integer> it=array.iterator();    Integer sum=0;    while(it.hasNext()){        sum +=it.next();    }    return sum;}public static boolean compareSum(ArrayList<Integer> sub1,ArrayList<Integer> sub2){    boolean flag=false;    int sum1=sumOfArray(sub1);    int sum2=sumOfArray(sub2);    if(sum1>sum2)        flag=true;    else        flag=false;    return flag;}}

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