算法1

DFS+BFS

一遍BFS求最短路,然后用一个数组保存路径,用一遍DFS打印路径

C++ 代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>

using namespace std;

const int maxn = 1005;

struct{
    int a, b;
}path[maxn][maxn];

bool vis[maxn][maxn] = {false};
int G[maxn][maxn], n, dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

void BFS(int x, int y)
{
    queue<pair<int, int> > q;
    q.push({x, y});
    while(!q.empty())
    {
        pair<int, int> temp = q.front();
        q.pop();
        for(int i = 0; i < 4; i++)
        {
            int nx = temp.first + dx[i];
            int ny = temp.second + dy[i];
            if(nx >= 0 && nx < n && ny >= 0 && ny < n && G[nx][ny] == 0)
            {
                if(vis[nx][ny] == false)
                {
                    q.push({nx, ny});
                    vis[nx][ny] = true;
                    path[nx][ny].a = temp.first;
                    path[nx][ny].b = temp.second; 
                }
            }
        }
    }
}

void DFS(int x, int y)
{
    if(x == 0 && y == 0)
    {
        printf("%d %d\n", x, y);
        return;
    }
    DFS(path[x][y].a, path[x][y].b);
    printf("%d %d\n", x, y);
}

int main()
{
    cin >> n;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            cin >> G[i][j];
    BFS(0, 0);
    DFS(n - 1, n - 1);
    return 0;
}