高分求解基本的java算法题

例如：
int[][] a=
{
{1,2,3,4,5},
{1,2,3,4,6},
{1,2,3,4,7}
};

行合并的规则为：两行中只相差一个数字，就把相差的数字进行合并，例如将a进行行合并处理后，变为：
int[][] b=
{
{1,2,3,4,11},
{1,2,3,4,7}
};

再对 b进行行合并后，变为：
int[][] c=
{
{1,2,3,4,18}
};

请用java写出能实现合并规则，行数最多可能为5万。

试写一个：
[code="java"]
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.junit.Test;

public class CombinArray {
public static ArrayList combine(ArrObject theArr,
ArrObject otherArr) {
List one = theArr.getArr();
List other = otherArr.getArr();
ArrayList combined = new ArrayList();
int noEqualCount = 0;
int equalCount = 0;
if (one.size() == other.size()) {
for (int i = 0; i < one.size(); i++) {
if (one.get(i) - other.get(i) != 0) {
noEqualCount++;
combined.add(one.get(i) + other.get(i));
} else {
equalCount++;
combined.add(one.get(i));
}
}
}
// Equal and have only one difference can combine to one.
if (noEqualCount == 1 || equalCount == one.size()) {
System.out.println("middle:" + combined);
return combined;
}
return null;
}

@Test
public void testCombine() {
    ArrObject arr1 = new ArrObject(Arrays.asList(1, 2, 3));
    ArrObject arr2 = new ArrObject(Arrays.asList(1, 2, 3));
    ArrObject arr3 = new ArrObject(Arrays.asList(1, 2, 8));
    ArrObject arr4 = new ArrObject(Arrays.asList(1, 3, 8));
    ArrObject arr5 = new ArrObject(Arrays.asList(1, 3, 8));
    ArrObject arr6 = new ArrObject(Arrays.asList(3, 8, 1));
    ArrayList<ArrObject> arrayList = new ArrayList<ArrObject>(
            Arrays.asList(arr1, arr2, arr3, arr4, arr5, arr6));
    ArrayList<ArrObject> resultList = new ArrayList<ArrObject>();
    for (int i = 0; i < arrayList.size(); i++) {
        ArrObject one = arrayList.get(i);
        ArrObject other = arrayList.get((i + 1) / arrayList.size());
        ArrayList<Integer> result = combine(one, other);
        if (result != null && !resultList.contains(result)) {
            arrayList.add(new ArrObject(result));
            arrayList.remove(one);
            arrayList.remove(other);
            resultList.add(new ArrObject(result));
        }
        print(arrayList);
    }
    System.out.println("==========result==========");
    print(resultList);
}

private void print(ArrayList<ArrObject> copyofList) {
    System.out.println("finished:");
    for (ArrObject arrObject : copyofList) {
        System.out.println(arrObject.getArr());
    }
}

}

class ArrObject {
private List arr;
private boolean combine;

public ArrObject(List<Integer> arr) {
    super();
    Collections.sort(arr);
    this.arr = arr;
}

public boolean isCombine() {
    return combine;
}

public void setCombine(boolean combine) {
    this.combine = combine;
}

public List<Integer> getArr() {
    return arr;
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((arr == null) ? 0 : arr.hashCode());
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    ArrObject other = (ArrObject) obj;
    if (arr == null) {
        if (other.arr != null)
            return false;
    } else if (!arr.equals(other.arr))
        return false;
    return true;
}

}
[/code]

两行中只相差一个数字，1，2,3,4 和 5,3,2,1算不算？

我觉得顺序无关紧要，可以排序，这样的算吗1，2，3 跟1，2。

暂时思路，先将相同的列去掉得到一个新的矩阵，然后求出这个矩阵的逆矩阵，将这两个矩阵补充为相同维数的矩阵（没有的用0补充），然后求他们的差，再根据矩阵的0来决策