[feat]: add naive final measure

ScQ-Cloud · Dec 21, 2023 · ac794a5 · ac794a5
1 parent 2e4d8e0
commit ac794a5
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Showing 2 changed files with 34 additions and 15 deletions.
diff --git a/src/qfvm/qfvm.cpp b/src/qfvm/qfvm.cpp
@@ -119,12 +119,9 @@ template <size_t word_size>
 std::map<uint, uint> simulate_circuit_clifford(const py::object& pycircuit, const int& shots) {
 
     auto circuit = Circuit(pycircuit);
-    auto global_cs = circuit_simulator<word_size>(circuit.qubit_num());
 
     // If measure all at the end, simulate once
     uint actual_shots = shots;
-    if (circuit.final_measure()) 
-        actual_shots = 1;
 
     // qbit, cbit
     vector<std::pair<uint, uint>> measures = circuit.measure_vec();
@@ -136,10 +133,11 @@ std::map<uint, uint> simulate_circuit_clifford(const py::object& pycircuit, cons
     // Store outcome's count
     std::map<uint, uint> outcount;
 
-    for(uint i =0; i < actual_shots; i++) {
+    circuit_simulator<word_size> cs(circuit.qubit_num());
 
-        circuit_simulator<word_size> cs(circuit.qubit_num());
+    for(uint i =0; i < actual_shots; i++) {
         simulate(circuit, cs);
+        uint outcome = 0;
 
         if (!circuit.final_measure()) {
             // qubit, cbit, measure result
@@ -149,24 +147,34 @@ std::map<uint, uint> simulate_circuit_clifford(const py::object& pycircuit, cons
             std::sort(measure_results.begin(), measure_results.end(), 
                 [](auto& a, auto& b) { return std::get<1>(a) < std::get<1>(b); });
 
-            uint outcome = 0;
             for (auto& measure_result: measure_results) {
                 outcome *= 2;
                 outcome += std::get<2>(measure_result);
             }
 
-            if (outcount.find(outcome) != outcount.end()) 
-                outcount[outcome]++;
-            else 
-                outcount[outcome] = 1;
+        } else if (circuit.final_measure() && !measures.empty()) {
+            for (auto& measure: measures) {
+                cs.do_circuit_instruction({"measure", std::vector<size_t>{measures[i].first}, std::vector<double>{static_cast<double>(measures[i].second)}});
+            }
+
+            // qubit, cbit, measure result
+            auto measure_results = cs.current_measurement_record();
+
+            // make sure the order is the same with other simulators
+            std::sort(measure_results.begin(), measure_results.end(), 
+                [](auto& a, auto& b) { return std::get<1>(a) < std::get<1>(b); });
+
+            for (auto& measure_result: measure_results) {
+                outcome *= 2;
+                outcome += std::get<2>(measure_result);
+            }
         }
 
-        if (circuit.final_measure() || i == actual_shots - 1) 
-            global_cs = std::move(cs);
-    }
+        if(outcount.find(outcome) != outcount.end()) outcount[outcome]++;
+        else outcount[outcome] = 1;
 
-    if (circuit.final_measure()) {
-        throw std::runtime_error("Not implemented");
+        cs.reset_tableau();
+        cs.sim_record.clear();
     }
 
     return outcount;

diff --git a/src/qfvm_clifford/clifford_simulator.h b/src/qfvm_clifford/clifford_simulator.h
@@ -25,6 +25,7 @@ struct measurement_record {
   auto cbegin() const { return storage.cbegin(); }
   auto cend() const { return storage.cend(); }
   auto size() const { return storage.size(); }
+  void clear() { storage.clear(); }
 };
 
 // quantum circuit simulator, include original tableau, measurement record and a
@@ -155,6 +156,16 @@ template <size_t word_size> struct circuit_simulator {
 
   // get the measurement record
   auto current_measurement_record() const { return sim_record; }
+
+  auto measure_all() {
+    measurement_record mr;
+    for (size_t i = 0; i < sim_tableau.num_qubits; i++) {
+      auto record = sim_tableau.m_gate(rng, i);
+      if (record.has_value())
+        mr.record(record.value());
+    }
+    return mr;
+  }
 };
 
 #endif