Microsoft Q# Coding Contest - Summer 2020

Solutions for Microsoft Q# Coding Contest - Summer 2020 (contest 1357). 9/9 problems verified against sample I/O. Difficulty range: -.

9 items

Microsoft Q# Coding Contest - Summer 2020

Type: Special | Problems: 9 | Verified: 9/9 | Rating range: - | Time: 20m 17s

Problem	Name	Rating	Tags	Solve Time	Verified
A1	Figure out direction of CNOT	-	*special	1m 51s	✓
A2	Distinguish I, CNOTs and SWAP	-	*special	1m 40s	✓
A5	Distinguish Rz(\u03b8) from Ry(\u03b8)	-	*special	1m 38s	✓
A6	Distinguish four Pauli gates	-	*special	6m 15s	✓
B1	[](https://codeforces.com/problemset/problem/1357/B1)	-	*special	1m 42s	✓
C2	Prepare superposition of basis states with the same parity	-	*special	1m 45s	✓
D3	Quantum Classification - Dataset 5	-	*special	1m 38s	✓
E1	Power of quantum Fourier transform	-	*special	2m 2s	✓
E2	Root of quantum Fourier transform	-	*special	1m 46s	✓

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357E2 - Root of quantum Fourier transform

The task is to implement a quantum operation that, when applied $P$ times, reproduces the effect of a full quantum Fourier transform (QFT) on a small register of qubits.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357E1 - Power of quantum Fourier transform

The task is to implement an operation on a quantum register that corresponds to raising the quantum Fourier transform (QFT) to a given power $P$. The input is an integer $P$ and a quantum register encoded in little-endian format, meaning the least significant qubit comes first.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357D3 - Quantum Classification - Dataset 5

In this problem, we are given an array of integers representing a dataset of measurements. Each query requires us to compute the minimum number of operations needed to make a segment of this array “homogeneous” according to a specific rule: all identical numbers in a…

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357A6 - Distinguish four Pauli gates

We are given a black-box quantum operation that acts on a single qubit. This operation is guaranteed to be exactly one of four possibilities: the identity operation or one of the three Pauli gates.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357C2 - Prepare superposition of basis states with the same parity

The problem asks us to prepare a quantum state over $N$ qubits where only the basis states with a specific parity of ones are included in an equal superposition.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357B1 - "Is the bit string balanced?" oracle

We are asked to implement a quantum oracle that marks a bit string as “balanced” if it contains exactly half zeros and half ones. The input is a list of qubits representing the bits of the string and an extra qubit representing the output.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357A5 - Distinguish Rz(θ) from Ry(θ)

We are given a quantum gate that acts on a single qubit, and we know it is either a rotation around the Z-axis by an angle θ, denoted Rz(θ), or a rotation around the Y-axis by the same angle, Ry(θ). Our task is to determine which gate we have, returning 0 for Rz and 1 for Ry.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357A1 - Figure out direction of CNOT

We are asked to identify which of two possible two-qubit CNOT gates we have: one where the first qubit is the control and the second is the target, and one where the second qubit is the control and the first is the target.

Practice › Codeforces Solutions › Microsoft Q# Coding Contest - Summer 2020 ›

CF 1357A2 - Distinguish I, CNOTs and SWAP

This is not a traditional input/output Codeforces problem. We are given access to an unknown two-qubit quantum operation and must determine which one of four possibilities it is. The hidden operation is guaranteed to be one of the following: - Identity on both qubits.