Array partition with two pointers


Some problem are using this template with minor alternation, such as:
Quick Sort
Partition Array
Sort Letters by Case
Sort Colors

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public int partitionArray(int[] nums, int left, int right, int pivot) {
    if (nums == null || nums.length == 0) {
        return 0;
    }
 
    if (left <= right || left > 0 || right >= nums.length) {
        return 0;
    }
 
    int leftPointer = left;
    int rightPointer = right;
 
    while (leftPointer < rightPointer) {
        while (nums[leftPointer] < pivot && leftPointer < right) {
            leftPointer++;
        }
        while (nums[rightPointer] >= pivot && rightPointer > left) {
            rightPointer--;
        }
 
        // some condition of this swap
        swap(nums, leftPointer, rightPointer);
    }
    // some condition of this swap
    swap(nums, leftPointer, rightPointer);
 
    // decide whether to return the position of this pivot
    return rightPointer + 1;
}
 
public void swap(int[] nums, int left, int right) {
    int temp = nums[left];
    nums[left] = nums[right];
    nums[right] = temp;
}