Used IQFT from header in the QPE example

#include "qcor.hpp"

// Use the pre-defined IQFT kernel

#include "qft.hpp"

// Example of Quantum Phase Estimation circuit using QCOR runtime.

// Compile with:

  }

  // Inverse QFT on the counting qubits:

  const int startIdx = bitPrecision / 2 - 1;

  for (int qIdx = startIdx; qIdx >= 0; --qIdx) {

    Swap(q[qIdx], q[bitPrecision - qIdx - 1]);

  }

  for (int qIdx = 0; qIdx < bitPrecision; ++qIdx) {

    for (int j = 0; j < qIdx; ++j) {

      const double theta = -M_PI/std::pow(2.0, qIdx - j);

      CPhase(q[j], q[qIdx], theta);

    }

    H(q[qIdx]);

  }

  inverseQuantumFourierTransform(q, bitPrecision);

  // Measure counting qubits

  for (int qIdx = 0; qIdx < bitPrecision; ++qIdx) {