priority_queue<Node*, vector<Node*>, CompareNode> openList;
时间: 2024-05-20 17:15:03 浏览: 15
这是一个定义了一个优先队列 `openList`,其中元素类型为 `Node*` 指针,使用的容器是 `vector<Node*>`,而比较函数则是 `CompareNode`。这个优先队列是用于实现某种搜索算法的,例如 A* 算法,其中需要根据某个评估函数的值对状态进行排序和选择。在搜索过程中,将状态依次加入到 `openList` 中,每次选取评估函数值最小的状态进行扩展和搜索。通过使用优先队列,可以很方便地实现这个过程。
相关问题
A*算法C++代码
以下是 A*算法的 C++ 代码示例:
```c++
#include <iostream>
#include <vector>
#include <queue>
#include <cmath>
using namespace std;
struct Node {
int x, y; // 节点坐标
int f, g, h; // f(x) = g(x) + h(x)
Node* parent; // 父节点指针
Node(int x, int y) : x(x), y(y), f(0), g(0), h(0), parent(nullptr) {};
};
// 比较函数
struct cmp {
bool operator()(Node* n1, Node* n2) {
return n1->f > n2->f;
}
};
class AStar {
public:
AStar(int rows, int cols, int startX, int startY, int endX, int endY, vector<vector<int>>& grids) {
this->rows = rows;
this->cols = cols;
this->startX = startX;
this->startY = startY;
this->endX = endX;
this->endY = endY;
this->grids = grids;
}
vector<Node*> findPath() {
vector<Node*> path;
Node* startNode = new Node(startX, startY);
Node* endNode = new Node(endX, endY);
priority_queue<Node*, vector<Node*>, cmp> openList; // 开启列表
vector<Node*> closeList; // 关闭列表
openList.push(startNode);
while (!openList.empty()) {
Node* curNode = openList.top();
openList.pop();
closeList.push_back(curNode);
if (curNode->x == endX && curNode->y == endY) {
// 找到路径
Node* node = curNode;
while (node) {
path.push_back(node);
node = node->parent;
}
reverse(path.begin(), path.end());
break;
}
for (int i = -1; i <= 1; i++) {
for (int j = -1; j <= 1; j++) {
if (i == 0 && j == 0) {
continue;
}
int xPos = curNode->x + i;
int yPos = curNode->y + j;
if (xPos < 0 || xPos >= rows || yPos < 0 || yPos >= cols) {
continue;
}
if (grids[xPos][yPos] == 1) {
continue;
}
bool inCloseList = false;
for (auto node : closeList) {
if (node->x == xPos && node->y == yPos) {
inCloseList = true;
break;
}
}
if (inCloseList) {
continue;
}
Node* childNode = new Node(xPos, yPos);
childNode->parent = curNode;
childNode->g = curNode->g + 1;
childNode->h = heuristic(childNode, endNode);
childNode->f = childNode->g + childNode->h;
bool inOpenList = false;
for (auto node : openList) {
if (node->x == xPos && node->y == yPos) {
inOpenList = true;
if (childNode->f < node->f) {
node->f = childNode->f;
node->g = childNode->g;
node->h = childNode->h;
node->parent = childNode->parent;
}
break;
}
}
if (!inOpenList) {
openList.push(childNode);
}
}
}
}
// 释放内存
for (auto node : closeList) {
delete node;
}
return path;
}
private:
int rows, cols; // 地图大小
int startX, startY, endX, endY; // 起点和终点坐标
vector<vector<int>> grids; // 地图数组
// 计算启发函数
int heuristic(Node* a, Node* b) {
return abs(a->x - b->x) + abs(a->y - b->y);
}
};
int main() {
int rows = 5, cols = 5;
int startX = 0, startY = 0;
int endX = 4, endY = 4;
vector<vector<int>> grids(rows, vector<int>(cols, 0));
grids[1][1] = 1;
grids[2][1] = 1;
grids[3][1] = 1;
AStar astar(rows, cols, startX, startY, endX, endY, grids);
vector<Node*> path = astar.findPath();
for (auto node : path) {
cout << "(" << node->x << "," << node->y << ")" << endl;
}
return 0;
}
```
用arduino ide写一个A*寻路算法
好的,以下是一个简单的 A* 寻路算法的实现,使用 Arduino IDE 编写:
```
#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
// 定义节点结构体
struct Node {
int x, y; // 节点坐标
int f, g, h; // f = g + h
Node* parent; // 父节点指针
Node(int _x, int _y) : x(_x), y(_y), f(0), g(0), h(0), parent(nullptr) {}
// 重载小于运算符,用于优先队列排序
bool operator<(const Node& other) const {
return f > other.f;
}
};
// 判断节点是否在地图范围内
bool isValid(int x, int y, int n, int m) {
return x >= 0 && x < n && y >= 0 && y < m;
}
// 判断节点是否是障碍物
bool isObstacle(int x, int y, vector<vector<int>>& grid) {
return grid[x][y] == 1;
}
// 计算两个节点之间的曼哈顿距离
int manhattanDistance(Node* a, Node* b) {
return abs(a->x - b->x) + abs(a->y - b->y);
}
// A* 寻路算法
vector<Node*> aStarSearch(vector<vector<int>>& grid, Node* start, Node* end) {
int n = grid.size(), m = grid[0].size();
vector<Node*> path;
// 定义开启列表和关闭列表
priority_queue<Node*> openList;
vector<Node*> closedList;
// 将起点加入开启列表
openList.push(start);
while (!openList.empty()) {
// 取出开启列表中 f 值最小的节点
Node* current = openList.top();
openList.pop();
// 如果当前节点是终点,返回路径
if (current->x == end->x && current->y == end->y) {
Node* node = current;
while (node != nullptr) {
path.push_back(node);
node = node->parent;
}
reverse(path.begin(), path.end());
break;
}
// 将当前节点加入关闭列表
closedList.push_back(current);
// 遍历当前节点周围的节点
for (int dx = -1; dx <= 1; dx++) {
for (int dy = -1; dy <= 1; dy++) {
if (dx == 0 && dy == 0) continue; // 忽略当前节点
int x = current->x + dx, y = current->y + dy;
if (!isValid(x, y, n, m) || isObstacle(x, y, grid)) continue; // 节点不在地图范围内或是障碍物
// 计算节点的 f, g, h 值
int g = current->g + 1;
int h = manhattanDistance(new Node(x, y), end);
int f = g + h;
// 如果节点已经在关闭列表中,忽略
bool inClosedList = false;
for (auto node : closedList) {
if (node->x == x && node->y == y) {
inClosedList = true;
break;
}
}
if (inClosedList) continue;
// 如果节点已经在开启列表中,更新节点的 f 值和父节点指针
bool inOpenList = false;
for (auto node : openList) {
if (node->x == x && node->y == y) {
inOpenList = true;
if (f < node->f) {
node->f = f;
node->g = g;
node->h = h;
node->parent = current;
}
break;
}
}
if (inOpenList) continue;
// 将节点加入开启列表
Node* node = new Node(x, y);
node->f = f;
node->g = g;
node->h = h;
node->parent = current;
openList.push(node);
}
}
}
return path;
}
// 测试
int main() {
vector<vector<int>> grid = {
{0, 0, 0, 0, 0},
{0, 1, 0, 1, 0},
{0, 0, 0, 0, 0},
{0, 1, 0, 1, 0},
{0, 0, 0, 0, 0}
};
Node* start = new Node(0, 0);
Node* end = new Node(4, 4);
vector<Node*> path = aStarSearch(grid, start, end);
for (auto node : path) {
cout << "(" << node->x << ", " << node->y << ") ";
}
cout << endl;
return 0;
}
```
希望这个代码能够帮到你!
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