java - 如何删除数组合并方法中的重复项？

Question

我有一个方法，它接受 2 个属性，即 2 个数组，并按升序合并它们。剩下的就是弄清楚如何删除重复项。代码如下:

public static int[] mergeArrays(int[] a, int[] b){

    int[] c = new int[a.length+b.length];
    int aIt = 0;
    int bIt = 0;

    while(true) {


        if(aIt < a.length && bIt < b.length) {
            if(a[aIt] == b[bIt]){
                c[aIt+bIt] = a[aIt++];
            }
            else{
                c[aIt+bIt] = b[bIt++];
            }
        } else if(aIt < a.length) {
            c[aIt+bIt] = a[aIt++];
        } else if(bIt < b.length) {
            c[aIt+bIt] = b[bIt++];
        } else {
            break;
        }
    }
    return c;
}

正如你所想象的，这是一项作业，所以我不应该使用任何外部库，否则这会容易得多。

我尝试了这种方法，但是当我在控制台中运行此代码时，它似乎将其放入一些永无休止的循环中，该循环完全消耗了我的 CPU 核心，直到我停止该进程:

public static int[] mergeArrays(int[] a, int[] b){

    int[] c = new int[a.length+b.length];
    int aIt = 0;
    int bIt = 0;
    int lastVal = 0;
    while(true) {
        if(c[aIt+bIt] == lastVal){
            continue;
        }
        else{
            if(aIt < a.length && bIt < b.length) {
                if(a[aIt] == b[bIt]){
                    c[aIt+bIt] = a[aIt++];
                    lastVal = c[aIt+bIt];
                }
                else{
                    c[aIt+bIt] = b[bIt++];
                    lastVal = c[aIt+bIt];
                }
            } else if(aIt < a.length) {
                c[aIt+bIt] = a[aIt++];
                lastVal = c[aIt+bIt];
            } else if(bIt < b.length) {
                c[aIt+bIt] = b[bIt++];
                lastVal = c[aIt+bIt];
            } else {
                break;
            }
        }
    }
    return c;
}

似乎“继续”关键字是问题所在。当我尝试在其位置中断时，代码就会执行。

编辑:

我已向 mergeArrays 方法添加了一个新数组:

public static int[] mergeArrays(int[] a, int[] b)
{
    int a_size = a.length;
    int b_size = b.length;
    int[] c = new int[a_size + b_size];
    int[] d = null;
    int i = 0 , j = 0, x = -1;
    for(; i < a_size && j < b_size;)
    {
        if(a[i] <= b[j])
        {
            c[++x] = a[i];
            ++i;
            }
        else          
        {
            if(c[x] != b[j])
            {
                c[++x] = b[j]; // avoid duplicates
            }
            ++j;
            }
            }
            --i; --j;
            while(++i < a_size)
            {
                c[++x] = a[i];
            }
            while(++j < b_size)
            {
                c[++x] = b[j];
            }
    d = new int[uniqueValues(c)];        

    for(int g=0; g<uniqueValues(c); g++){
        d[g] = c[g];
    }
    return d;
}

Answer 1

那么您当然可以通过以下两个步骤完成这些任务:

Sort both the arrays.

static void sortArray(int[] a) {
    for (int lastPos = a.length - 1; lastPos >= 0; lastPos--) {
        for (int index = 0; index <= lastPos - 1; index++) {
            if (a[index] > a[index + 1]) {
                int temp = a[index];
                a[index] = a[index + 1];
                a[index + 1] = temp;
            }
        }
    }
}

Remove duplicates while merging them.

public static int[] mergeArrays(int[] a, int[] b)
        {
            int a_size = a.length;
            int b_size = b.length;
            int[] c = new int[a_size + b_size];
            int i = 0 , j = 0, x = -1;
            for(; i < a_size && j < b_size;)
            {
                if(a[i] <= b[j])
                {
                    c[++x] = a[i];
                    ++i;
                    }
                else          
                {
                    if(c[x] != b[j])
                    {
                        c[++x] = b[j]; // avoid duplicates
                    }
                    ++j;
                    }
                    }
                    --i; --j;
                    while(++i < a_size)
                    {
                        c[++x] = a[i];
                    }
                    while(++j < b_size)
                    {
                        c[++x] = b[j];
                    }
                    return c;
                    }

Count unique values in newly merged array.

static int uniqueValues(int[] c) {
    int uniqueValues = c.length;
    for (int i = 0; i < c.length; i++) {
        while (c[i] == c[i + 1] && i + 1 < c.length && c[i] > c[i+1] ) {
            i++;
            uniqueValues--;
        }
    }
    return unique;
}

Reestablish the merged array with unique value count i.e. delete the remaining elements after count finishes.

sortArray(a);
sortArray(b);
int[] c = mergeArrays(a, b);
c = deleteDuplicateEntries(c, uniqueValues(c));

如果您觉得它有用，请告诉我。