根据另一个数组的值对一个数组排序

Question

I want to sort an array, the problem is that each element of the array has certain values in another array for example first array={31,12,88,74,55} Second array={5,2,3,3,5} On sorting the second array elements in descending order the corresponding values in the first array has to be interchanged. First array={31,55,74,88,12} Second array={5,5,3,3,2}

Answer 1

Sounds like you short be storing an array of objects, where each object has two values.

public class X implements Comparable<X> {
    private int a;
    private int b;

    public X(int a, int b) {
        this.a = a;
        this.b = b;
    }

    public int compareTo(X other) {
        return a - other.a;
    }
}

Then you can make a list of these items, and sort them.

List<X> items = ... // Fill in the blanks
Collections.sort(items);

Answer 2

You can simply write two for loops to sort the second array, and make the same changes to the first array at the same time.

for (int i = 0; i < array2.length; i++){
    for (int j = 0; j < array2.length; j++){
        if (array2[i] < array2[j] && i < j){
            int temp1 = array1[i];
            int temp2 = array2[i];

            array1[i] = array1[j];
            array2[i] = array2[j];

            array1[j] = temp1;
            array2[j] = temp2;
        }
    }
}

While the second array is being sorted, the first array's elements are being moved the exact same way, regardless of their values.

Hope this helps!