启发式搜索

A*搜索

代码演示

/*************************************************************************
        > File Name: A星搜索.cpp
        > Author:
        > Mail:
        > Created Time: Thu 14 Oct 2021 07:50:55 PM CST
 ************************************************************************/

#include <iostream>
#include <queue>
#include <cstdio>
#include <cmath>
#include <algorithm>

using namespace std;

struct Node {
    int x, y, step;
    double dis;
    bool operator< (const Node &a) const {
        return this->step + this->dis > a.step + a.dis;
    }
};

int n, m, sx, sy, tx, ty, cnt;
int dis[8][2] = {1, 1, 1, -1, 1, 0, -1, -1, -1, 1, -1, 0, 0, 1, 0, -1};
char mmap[102][102];
int ans[102][102][2];
double func(int x, int y) { // 计算欧式距离
    int t1 = x - tx;
    int t2 = y - ty;
    return sqrt(t1 * t1 + t2 * t2);
}

void func2(int x, int y) { // 回溯路径
    if (mmap[x][y] == 'S') {
        return ;
    }
    mmap[x][y] = 'o';
    func2(ans[x][y][0], ans[x][y][1]);
    return ;
}

void p_out() { //打印地图
    printf("............................cnt = %d ............................\n", cnt);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cout << mmap[i][j];
            if (mmap[i][j] == 'x') mmap[i][j] = 'X';
        }
        cout << endl;
    }
    printf("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$\n");
    return ;
}

int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> mmap[i][j];
            if (mmap[i][j] == 'S') sx = i, sy = j;
            if (mmap[i][j] == 'T') tx = i, ty = j;
        }
    }
    priority_queue <Node> q;
    q.push((Node){sx, sy, 0, func(sx, sy)});
    while (!q.empty()) {
        Node tp = q.top();
        q.pop();
        for (int i = 0; i < 8; i++) {
            int dx = tp.x + dis[i][0];
            int dy = tp.y + dis[i][1];
            if (mmap[dx][dy] == 'T') {
                func2(tp.x, tp.y);
                p_out();
                cout << tp.step + 1 << endl;
                return 0;
            }
            if (mmap[dx][dy] == '.') {
                mmap[dx][dy] = 'x';
                cnt++;
                if (cnt % 10 == 0) {
                    p_out();
                }
                ans[dx][dy][0] = tp.x; //标记当前坐标从那个坐标来
                ans[dx][dy][1] = tp.y;
                q.push((Node){dx, dy, tp.step + 1, func(dx, dy)});
            }
        }
    }
    return 0;
}