added Astar

SolovevDS/docs/data/data_for_task2/task2.cpp

@@ -2,6 +2,7 @@
 #include <iostream>
 #include <string>
 #include <stdexcept>
+#include <cmath>
 
 class cell{
     private:
@@ -373,9 +374,6 @@ class DFSStrategy : public PathFindingStrategy {
             bool** visited = new bool*[width];
             cell*** parent = new cell**[width];
 
-            
-            cell** stack = new cell*[width * height];
-            int top = 0;
             for (int x = 0; x < width; x++) {
                 visited[x] = new bool[height];
                 parent[x] = new cell*[height];
@@ -386,6 +384,8 @@ class DFSStrategy : public PathFindingStrategy {
                 }
             }
 
+            cell** stack = new cell*[width * height];
+            int top = 0;
             stack[top] = start;
             top++;
             visited[start->getX()][start->getY()] = true;
@@ -442,9 +442,143 @@ class DFSStrategy : public PathFindingStrategy {
 };
 
 class AStarStrategy : public PathFindingStrategy {
+    private:
+        int heuristic(cell* current, cell* exit) {return std::abs(current->getX() - exit->getX()) + std::abs(current->getY() - exit->getY());}
+
     public:
         cell** findPath(maze* m, cell* start, cell* exit) override {
-            // здесь будет алгоритм A*
+            int width = m->getWidth();
+            int height = m->getHeight();
+
+            bool** closed = new bool*[width];   /*клетка [x][y] посещена (да/нет)*/
+            bool** inOpen = new bool*[width];   /*клетка [x][y] имеет потенциал к посещению (да/нет)*/
+            int** gScore = new int*[width];     /* до клетка [x][y] от старта gSchore[x][y] шагов*/
+            int** fScore = new int*[width];     /*f = h + g, где g - эвристика клетки[x][y]*/
+
+            cell*** parent = new cell**[width];
+
+
+            for (int x = 0; x < width; x++) {
+                closed[x] = new bool[height];
+                inOpen[x] = new bool[height];
+                gScore[x] = new int[height];
+                fScore[x] = new int[height];
+
+                parent[x] = new cell*[height];
+
+                for (int y = 0; y < height; y++) {
+                    closed[x][y] = false;
+                    inOpen[x][y] = false;
+
+                    gScore[x][y] = width * height + 100000; /*тупо большое число чтоб было больше чем клеток в лаберинте*/
+                    fScore[x][y] = width * height + 100000;
+
+                    parent[x][y] = nullptr;
+                }
+            }
+
+            cell** open = new cell*[width * height]; /*клетки с потенциалом на посещение*/
+            int openCount = 0; /*это количество потенц клеток, а также индекс следующего незанятого места*/
+
+            int sx = start->getX();
+            int sy = start->getY();
+
+            gScore[sx][sy] = 0;
+            fScore[sx][sy] = heuristic(start, exit);
+
+            open[openCount] = start;
+            openCount++;
+
+            inOpen[sx][sy] = true;
+            bool found = false;
+
+            while (openCount > 0) {
+                int bestIndex = 0;
+
+                for (int i = 1; i < openCount; i++) {
+                    int ix = open[i]->getX();
+                    int iy = open[i]->getY();
+
+                    int bx = open[bestIndex]->getX();
+                    int by = open[bestIndex]->getY();
+
+                    if (fScore[ix][iy] < fScore[bx][by]) {
+                        bestIndex = i; /*(fSchore наименьший в [bestIndex])*/
+                    }
+                }
+
+                cell* current = open[bestIndex];
+
+                if (current == exit) {
+                    found = true;
+                    break;
+                }
+
+                int cx = current->getX();
+                int cy = current->getY();
+
+                open[bestIndex] = open[openCount - 1];
+                openCount--;
+
+                inOpen[cx][cy] = false;
+                closed[cx][cy] = true;
+
+                cell** neighbors = m->getNeighbors(current);
+
+                for (int i = 0; neighbors[i] != nullptr; i++) {
+                    cell* next = neighbors[i];
+
+                    int nx = next->getX();
+                    int ny = next->getY();
+
+                    if (closed[nx][ny]) {
+                        continue;
+                    }
+
+                    int tentativeG = gScore[cx][cy] + 1;
+
+                    if (tentativeG < gScore[nx][ny]) {
+                        parent[nx][ny] = current;
+
+                        gScore[nx][ny] = tentativeG;
+                        fScore[nx][ny] = gScore[nx][ny] + heuristic(next, exit);
+
+                        if (!inOpen[nx][ny]) {
+                            open[openCount] = next;
+                            openCount++;
+
+                            inOpen[nx][ny] = true;
+                        }
+                    }
+                }
+                delete[] neighbors;
+            }
+
+            cell** path;
+            if (found) {
+                path = PathBuilder::buildPath(start, exit, parent);
+            }
+            else {
+                path = new cell*[1];
+                path[0] = nullptr;
+            }
+
+            delete[] open;
+
+            for (int x = 0; x < width; x++) {
+                delete[] closed[x];
+                delete[] inOpen[x];
+                delete[] gScore[x];
+                delete[] fScore[x];
+                delete[] parent[x];
+            }
+            delete[] closed;
+            delete[] inOpen;
+            delete[] gScore;
+            delete[] fScore;
+            delete[] parent;
+
+            return path;
         }
 };