ожидается '' перед '{' лексема

Question

я получаю сообщение Graph.h: В функции 'Ьоо has_cycle (G &)': Graph.h: 392: 5: ошибка: ожидается ';' перед ' {'token Я проверил все фигурные скобки, они сбалансированы, я не могу понять, почему I

ошибка происходит в функции has_cycle. Мне интересно, если это связано с аргументами функции шаблона

#ifndef Graph_h 
#define Graph_h 

// -------- 
// includes 
// -------- 

#include <cassert> // assert 
#include <cstddef> // size_t 
#include <utility> // make_pair, pair 
#include <deque> // deque 
#include <unordered_map> // unordered_map 
#include <unordered_set> // unordered set 
#include <iterator> 
#include <algorithm> 
#include "boost/graph/exception.hpp"// not_a_dag exception 

// ----- 
// Graph 
// ----- 

class Graph 
{ 

public: 

    //EdgeDescriptor Class 
class EdgeDescriptor 
{ 
    public: 
     std::size_t _source; /*!< source vertex_descriptor */ 
     std::size_t _target; /*!< target vertex_descriptor */ 

    /** 
    * default constructor 
    */ 
    EdgeDescriptor() 
    {} 

    /** 
    * constructor 
    * @param s the sourse vertex_descriptor 
    * @param t the target vertex_descriptor 
    */ 
    EdgeDescriptor(std::size_t s, std::size_t t) 
    { 
     _source = s; 
     _target = t; 
    } 

    /** 
    * == operator for EdgeDescriptor 
    * @param lhs a EdgeDescriptor 
    * @param rhs a EdgeDescriptor 
    * @return a bool that indicates whether the EdgeDescriptors are equal 
    */ 
    friend bool operator == (const EdgeDescriptor& lhs, const EdgeDescriptor& rhs) 
    { 
     return (lhs._source == rhs._source) && (lhs._target == rhs._target); 
    } 

}; 

    // -------- 
    // typedefs 
    // -------- 

    typedef std::size_t vertex_descriptor; 
    typedef EdgeDescriptor edge_descriptor; 

    typedef std::deque<vertex_descriptor>::iterator vertex_iterator; 
    typedef std::unordered_set<edge_descriptor>::iterator edge_iterator; 
    typedef std::deque<vertex_descriptor>::iterator adjacency_iterator; 

    typedef std::size_t vertices_size_type; 
    typedef std::size_t edges_size_type; 

public: 
    // -------- 
    // add_edge 
    // -------- 

    /** 
    * possibly add an edge_descriptor between two given vertex_descriptor to the graph 
    * @param v1 a vertex_descriptor 
    * @param v2 a vertex_descriptor 
    * @return a pair where first of the pair is the edge_descriptor added and second of the pair indicates whether the EdgeDescriptor has been successfully added 
    */ 
    friend std::pair<edge_descriptor, bool> add_edge (vertex_descriptor v1, vertex_descriptor v2, Graph& g) 
    { 
     edge_descriptor e(v1, v2); 

     //check if the edge_descriptor exists in the graph 
     if(g._edges.find(e) == g._edges.end()) 
     { 
      /* If the VertexList selector is vecS, and if either vertex descriptor u or v (which are integers) has a value greater than the current number of vertices in the graph, 
      the graph is enlarged so that the number of vertices is std::max(u,v) + 1. */ 
      if((v1 >= g._vertices.size()) || (v2 >= g._vertices.size())) 
      { 
       std::size_t new_size = std::max(v1, v2) + 1; 
       g._vertices.resize(new_size); 
      } 

      g._targets[v1].push_back(v2); //add v1's adjacent vertex_descriptor (which is v2) 

      g._edges.insert(e); //add edge_descriptor 

      return std::make_pair(e, true); 
     } 
     else 
     { 
      return std::make_pair(e, false); 
     } 
    } 

    // ---------- 
    // add_vertex 
    // ---------- 

    /** 
    * add a vertex_descriptor to the graph 
    * @param g the graph where vertex_descriptor is added 
    * @return the vertex_descriptor added 
    */ 
    friend vertex_descriptor add_vertex (Graph& g) 
    { 
     g._vertices.push_back((g._vertices.size()) + 1); 
     return g._vertices.back(); 
    } 

    // ----------------- 
    // adjacent_vertices 
    // ----------------- 

    /** 
    * adjacent_vertices function 
    * @param v a vertex_descriptor 
    * @param g the graph where the vertex_descriptor is 
    * @return a pair of adjacency_iterators, where the first iterator can travel to the second one the eventually visit all the adjacent vertices of the vertex_descriptor 
    */ 
    friend std::pair<adjacency_iterator, adjacency_iterator> adjacent_vertices (vertex_descriptor v, Graph& g) 
    { 
     return std::make_pair(((g._targets.find(v))->second).begin(), ((g._targets.find(v))->second).end()); 
    } 

    // ---- 
    // edge 
    // ---- 

    /** 
    * edge function 
    * @param v1 a vertex_descriptor 
    * @param v2 a vertex_descriptor 
    * @param g the graph where the vertex_descriptor is 
    * @return a pair, where first is the edge_descriptor between the vertices, second is a bool indicates whether the edge_descriptor exists in the graph 
    */ 
    friend std::pair<edge_descriptor, bool> edge (vertex_descriptor v1, vertex_descriptor v2, const Graph& g) 
    { 
     edge_descriptor e(v1, v2); 
     if(g._edges.find(e) == g._edges.end()) 
     { 
      return std::make_pair(e, true); 
     } 
     else 
     { 
      return std::make_pair(e, false); 
     } 
    } 

    // ----- 
    // edges 
    // ----- 

    /** 
    * edges function 
    * @param g a Graph 
    * @return a pair of edge_iterator in which the first can travel to the second one the eventually visits all the edges in the given graph 
    */ 
    friend std::pair<edge_iterator, edge_iterator> edges (Graph& g) 
    { 
     return std::make_pair(g._edges.begin(), g._edges.end()); 
    } 

    // --------- 
    // num_edge 
    // --------- 

    /** 
    * num_edge function 
    * @param g a Graph 
    * @return the number of edges in the given graph 
    */ 
    friend edges_size_type num_edge (const Graph& g) 
    { 
     return g._edges.size(); 
    } 

    // ------------ 
    // num_vertices 
    // ------------ 

    /** 
    * num_vertices function 
    * @param g a Graph 
    * @return the number of vertices in the given graph 
    */ 
    friend vertices_size_type num_vertices (const Graph& g) 
    { 
     return g._vertices.size(); 
    } 

    // ------ 
    // source 
    // ------ 

    /** 
    * source function 
    * @param r an edge_descriptor 
    * @param g a Graph 
    * @return the source vertex_descriptor of a given edge_descriptor in the given graph 
    */ 
    friend vertex_descriptor source (edge_descriptor e, const Graph& g) 
    { 
     return (g._edges.find(e))->_source; 
    } 

    // ------ 
    // target 
    // ------ 

    /** 
    * target function 
    * @param e an edge_descriptor 
    * @param g a Graph 
    * @return the target vertex_descriptor of a given edge_descriptor in the given graph 
    */ 
    friend vertex_descriptor target (edge_descriptor e, const Graph& g) 
    { 
     return (g._edges.find(e))->_target; 
    } 

    // ------ 
    // vertex 
    // ------ 

    /** 
    * vertex function 
    * @param nth integral value represents the n term index of the vertex 
    * @param g a Graph 
    * @return the nth vertex_descriptor of the graph 
    */ 
    friend vertex_descriptor vertex (vertices_size_type nth, const Graph& g) 
    { 
     return g._vertices[nth]; 
    } 

    // -------- 
    // vertices 
    // -------- 

    /** 
    * vertices function 
    * @param g a Graph 
    * @return a pair of vertex_iterator in which the first can travel to the second one the eventually visits all the vertices in the given graph 
    */ 
    friend std::pair<vertex_iterator, vertex_iterator> vertices (Graph& g) 
    { 
     return std::make_pair(g._vertices.begin(), g._vertices.end()); 
    } 

private: 
    // ---- 
    // data 
    // ---- 

    std::deque<vertex_descriptor> _vertices; /*!< container of the vertex_descriptors */ 

    std::unordered_set<edge_descriptor> _edges; /*!< container of the edge_descriptors */ 

    std::unordered_map<vertex_descriptor, std::deque<vertex_descriptor> > _targets; /*!< keep track of the adjacent vertices (vertex_descriptor that vertex_descriptors points to). Key is the vertex_descriptor that owns the adjacent vertex_descriptors*/ 


    // ----- 
    // valid 
    // ----- 

    /** 
    * valid function 
    */ 
    bool valid() const 
    { 
     return _vertices.size() == 0 && _edges.size() == 0 && _targets.size() == 0; 
    } 

public: 
    // ------------ 
    // constructors 
    // ------------ 

    /** 
    * default constructor 
    */ 
    Graph() : _vertices(), _edges(), _targets() 
    { 
     assert(valid()); 
    } 

    // Default copy, destructor, and copy assignment 
    // Graph (const Graph<T>&); 
    // ~Graph(); 
    // Graph& operator = (const Graph&); 
}; 

//helper function for has_cycle 
template <typename G> 
bool has_grey_neighbour (const G& g, typename G::vertex_descriptor v, std::vector<int>& colors) 
{ 
return std::any_of(adjacent_vertices(v, g).first, adjacent_vertices(v, g).second, [&colors](typename G::vertex_descriptor v) 
    { 
     return colors[v] == 1; 
    }); 
} 

//helper function for DFS (return -1 if no) 
template <typename G> 
int get_white_vertex (const G& g, std::vector<int>& colors) 
{ 
int result = -1; 
int count = 0; 
while(count < colors.size() && result == -1) 
{ 
    if(colors[count] == 0) 
    { 
     result = count; 
    } 
    ++count; 
} 
return result; 
} 

//helper function for DFS (return -1 if no white neighbour) 
template <typename G> 
int get_white_neighbour (const G& g, typename G::vertex_descriptor v, std::vector<int>& colors) 
{ 
typename G::adjacency_iterator match; 
match = std::find_if(adjacent_vertices(v, g).first, adjacent_vertices(v, g).second, [&colors](typename G::vertex_descriptor v) 
    { 
     return colors[v] == 0; 
    }); 
if(match == adjacent_vertices(v, g).second) 
{ 
    return -1; 
} 
else 
{ 
    return (int)(*match); 
} 
} 

// --------- 
// has_cycle 
// --------- 

/** 
* depth-first traversal 
* three colors 
* @param g a Graph 
* @return bool indicates whether the graph is cyclic 
*/ 
template <typename G> 
bool has_cycle (const G& g) 
{ 
if(num_vertices(g) == 0) 
{ 
    return false; 
} 

std::vector<int> colors(num_vertices(g), 0); //keep track of the different colors of vertices (0 while, 1 grey, 2 black) 
std::deque<typename G::vertex_descriptor> s; //use as a stack 
typename G::vertex_descriptor current_vertex; 
int current_vertex_index; 
int next_vertex_index; 
bool stack_empty; 

whlie(get_white_vertex(g, colors) != -1) 
{ 
    current_vertex_index = get_white_vertex(g, colors); 
    current_vertex = vertex(current_vertex_index, g); 
    colors[current_vertex_index] = 1; 
    do 
    { 
     if(has_grey_neighbour(g, current_vertex, colors)) 
     { 
      return true; 
     } 
     if((next_vertex_index = get_white_neighbour(g, current_vertex, colors)) != -1) 
     { 
      colors[next_vertex_index] = 1; 
      s.push_back(current_vertex); 
      current_vertex = vertex(next_vertex_index, g); 
      current_vertex_index = (int)current_vertex; 
     } 
     else 
     { 
      colors[current_vertex_index] = 2; 
      if(!(stack_empty = s.empty())) 
      { 
       current_vertex = s.back(); 
       current_vertex_index = (int)current_vertex; 
       s.pop_back(); 
      } 
     } 
    }while(!stack_empty); 
} 
return false; 
} 

// ---------------- 
// topological_sort 
// ---------------- 

/** 
* depth-first traversal 
* two colors 
* performs a topological sort on a graph and stream the outoput to an output iterator 
* @param g a Graph 
* @param x an output iteration 
* @throws Boost's not_a_dag exception if has_cycle() 
*/ 
template <typename G, typename OI> 
void topological_sort (const G& g, OI x) 
{ 
if(has_cycle(g)) 
{ 
    throw boost::not_a_dag(); 
} 
else 
{ 
    std::vector<int> colors(num_vertices(g), 0); //keep track of the different colors of vertices (0 while, 1 grey, 2 black) 
    std::deque<typename G::vertex_descriptor> s; //use as a stack 
    int current_vertex_index; 
    int next_vertex_index; 
    bool stack_empty; 
    typename G::vertex_descriptor current_vertex; 

    std::deque<typename G::vertex_descriptor> result; 

whlie((current_vertex_index = get_white_vertex(g, colors)) != -1) 
{ 
    current_vertex = vertex(current_vertex_index, g); 
    colors[current_vertex_index] = 1; 
    do 
    { 
     if((next_vertex_index = get_white_neighbour(g, current_vertex, colors)) != -1) 
     { 
      colors[next_vertex_index] = 1; 
      s.push_back(current_vertex); 
      current_vertex = vertex(next_vertex_index, g); 
      current_vertex_index = (int)current_vertex; 
     } 
     else 
     { 
      colors[current_vertex_index] = 2; 
      if(!(stack_empty = s.empty())) 
      { 
       current_vertex = s.back(); 
       current_vertex_index = (int)current_vertex; 
       s.pop_back(); 
      } 
     } 
    }while(!stack_empty); 
} 

    while(!result.empty()) 
    { 
     *x = result.back(); 
     result.pop_back(); 
     ++x; 
    } 
} 
} 

#endif // Graph_h 

Answer 1

While написано неправильно на этой линии:

whlie((current_vertex_index = get_white_vertex(g, colors)) != -1)