题解 | 迷宫问题

#include <iostream>
#include<bits/stdc++.h>
#include <vector>
using namespace std;

int main() {
    int h, w;cin>>h>>w;
    vector<vector<int>>grid(h,vector<int>(w));
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>grid[i][j];
        }
    }
    int orient[4][2]={1,0,0,1,-1,0,0,-1};
    queue<int>que;
    int x,y;
    que.push(0);que.push(0);
    grid[0][0]=1;
    vector<vector<int>>fromX(h,vector<int>(w,-1));
    vector<vector<int>>fromY(h,vector<int>(w,-1));
    fromX[0][0]=0;fromY[0][0]=0;
    while(!que.empty()){
        // cout<<"进入";
        x=que.front();que.pop();
        y=que.front();que.pop();
        //  cout<<"x="<<x<<",y="<<y<<endl;
         if(x==h-1&&y==w-1){break;}
        for(int i=0;i<4;i++){
            int x1=x+orient[i][0];
            int y1=y+orient[i][1];
            // cout<<"x1="<<x1<<",y1="<<y1<<endl;
            if(x1>=0&&x1<h&&y1>=0&&y1<w){
                if(grid[x1][y1]==0){
                    que.push(x1);
                    que.push(y1);
                    grid[x1][y1]=1;
                    fromX[x1][y1]=x;
                    fromY[x1][y1]=y;
                }
            }
        }
    }
    stack<int>stk;
     x=h-1,y=w-1;
    
    while (!(x==0&&y==0)) {
        stk.push(x);stk.push(y);
        int x1=fromX[x][y];
       int y1=fromY[x][y];
       x=x1;y=y1;
    //  cout<<"x="<<x<<",y="<<y<<endl;

    }
    stk.push(0);stk.push(0);
    while (!stk.empty()) {
    y=stk.top();stk.pop();
    x=stk.top();stk.pop();
    cout<<"("<<x<<","<<y<<")"<<endl;
    
    }
    

}
// 64 位输出请用 printf("%lld")

广搜作法：我说真的这题就不该用广搜。啊，不对，最短路径必须用广搜。

深搜法：

#include <iostream>
#include<bits/stdc++.h>
#include <vector>
using namespace std;
int orient[4][2] = {1, 0, 0, 1, -1, 0, 0, -1};
vector<pair<int, int>>path;

void dfs(vector<vector<int>>& grid, int x, int y) {
    path.push_back({x, y});
    if (x == grid.size() - 1 && y == grid[0].size() - 1) {
        for (auto it : path) {
            cout << "(" << it.first << "," << it.second << ")" << endl;
        }


        // cout << "找到了";
        return;
    }
    for (int i = 0; i < 4; i++) {
        int x1 = x + orient[i][0];
        int y1 = y + orient[i][1];
        // cout<<"x1="<<x1<<",y1="<<y1<<endl;
        if (x1 >= 0 && x1 < grid.size() && y1 >= 0 && y1 < grid[0].size()) {
            if (grid[x1][y1] == 0) {
                grid[x1][y1] = 1;
                dfs(grid, x1, y1);
                // grid[x1][y1] = 0;
            }
        }
    }
    path.pop_back();//注意回溯
}

int main() {
    int h, w;
    cin >> h >> w;
    vector<vector<int>>grid(h, vector<int>(w));
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            cin >> grid[i][j];
        }
    }

    queue<pair<int, int>>que;
    int x, y;
    que.push({0, 0});
    grid[0][0] = 1;
    path.clear();
    dfs(grid, 0, 0);



}
// 64 位输出请用 printf("%lld")