迷宫收集星星 并查集解答

群里发的来历不明的题目 可使用深搜广搜解决 我试了试并查集 效率不是很高

题目描述

解答 并查集

#include <iostream>
#include <vector>


using namespace std;
const int maxn = 1e5 + 7;
int pre[maxn];

int Find(int x)
{
    int p, tmp;
    p = x;
    while (x != pre[x])
        x = pre[x];
    while (p != x)
    {
        tmp = pre[x];
        pre[x] = x;
        p = tmp;
    }
    return x;
}

void join(int x, int y)
{
    int fx = Find(x);
    int fy = Find(y);
    if (fx != fy)
        pre[fx] = fy;
}

bool Same(int x, int y)
{
    return Find(x) == Find(y);
}


int m = 4; int n = 8;

vector<vector<char>> vmap(4, vector<char>(8, '.'));

void Init()
{
    vmap[0][2] = '#';
    vmap[0][6] = '*';

    vmap[1][0] = '*';
    vmap[1][2] = '#';
    vmap[1][4] = 'S';
    vmap[1][5] = '#';

    vmap[2][0] = '#';
    vmap[2][1] = '#';
    vmap[2][2] = '#';
    vmap[2][3] = '#';
    vmap[2][4] = '#';
    vmap[2][5] = '#';

    vmap[3][1] = '*';
    vmap[3][4] = '#';
    vmap[3][6] = '*';

    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 8; j++) {
            cout << vmap[i][j] << " ";
        }
        cout << endl;
    }

    for (int i = 0; i < maxn; i++) {
        pre[i] = i;
    }
         

}

int GetId(int x, int y)
{
    return (x +1)* 10 + (y+1);
}

int main()
{
    //std::cout << "Hello World!
"; 
    Init();
    int myId = -1;
    vector<int> record;
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 8; j++) {
            if (vmap[i][j] == '#')
                continue;

            if ((i + 1) < 4 && vmap[i+1][j] != '#') {
                int Id = GetId(i, j);
                int Id1 = GetId(i + 1, j);
                join(Id ,Id1);
            }
            
            if ((j + 1) < 8 && vmap[i][j+1] != '#')
            {
                int Id = GetId(i, j);
                int Id1 = GetId(i , j+1);
                join(Id, Id1);

            }
             
            if ((i - 1) > 0 && vmap[i - 1][j] != '#') {
                int Id = GetId(i, j);
                int Id1 = GetId(i - 1, j);
                join(Id, Id1);
            
            }
            
            if ((j - 1) > 0 && vmap[i][j - 1] != '#') {
                int Id = GetId(i, j);
                int Id1 = GetId(i , j-1);
                join(Id, Id1);
            }

            if (vmap[i][j] == '*') {
                record.push_back(GetId(i,j));
            }
            else if (vmap[i][j] == 'S') {
                myId = GetId(i, j);
            }
        }
    }
    int count = 0;
    for (auto& e : record) {
        if (Same(e, myId)) {
            count++;
        }
    }
    cout << count;
}