//===- Solution.h - PBQP Solution -------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// PBQP Solution class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_PBQP_SOLUTION_H
#define LLVM_CODEGEN_PBQP_SOLUTION_H

#include "llvm/CodeGen/PBQP/Graph.h"
#include <cassert>
#include <map>

namespace llvm {
namespace PBQP {

  /// \brief Represents a solution to a PBQP problem.
  ///
  /// To get the selection for each node in the problem use the getSelection method.
  class Solution {
  private:
    using SelectionsMap = std::map<GraphBase::NodeId, unsigned>;
    SelectionsMap selections;

    unsigned r0Reductions = 0;
    unsigned r1Reductions = 0;
    unsigned r2Reductions = 0;
    unsigned rNReductions = 0;

  public:
    /// \brief Initialise an empty solution.
    Solution() = default;

    /// \brief Set the selection for a given node.
    /// @param nodeId Node id.
    /// @param selection Selection for nodeId.
    void setSelection(GraphBase::NodeId nodeId, unsigned selection) {
      selections[nodeId] = selection;
    }

    /// \brief Get a node's selection.
    /// @param nodeId Node id.
    /// @return The selection for nodeId;
    unsigned getSelection(GraphBase::NodeId nodeId) const {
      SelectionsMap::const_iterator sItr = selections.find(nodeId);
      assert(sItr != selections.end() && "No selection for node.");
      return sItr->second;
    }
  };

} // end namespace PBQP
} // end namespace llvm

#endif // LLVM_CODEGEN_PBQP_SOLUTION_H
