1470. Shuffle the Array

Problem Statement

Shuffle the Array - LeetCode Given the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn].

Return the array in the form [x1,y1,x2,y2,...,xn,yn].

Pattern: Pattern 2 values in 1 variable

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Solution

public int[] shuffle (int[] nums, int n){
	// 1024 is upper constraint of nums[i], so can be taken as constVal
	final int constVal = 1024;
	// store array in second half
	for (int i = n; i < 2*n; i++) {
		nums[i] = nums[i-n] + (constVal * nums[i]);
	}
	
	// retrieve pairs from second half, write to adjacent pairs
	int index = 0;
	for (int i = n; i < 2 * n; i++, index+=2) {
		nums[index] = nums[i] % constVal;
		nums[index+1] = nums[i] / constVal;
	}
	
	return nums;
}

Notes

• Store both i and i+n values in the right half of the array
• Rewrite adjacent pairs from the begnining of the array, using the second half of the array.