迷宮收集星星 並查集解答

羣裏發的來歷不明的題目 可以使用深搜廣搜解決 我試了試並查集 效率不是很高

 

題目描述

 

解答 並查集

  1 #include <iostream>
  2 #include <vector>
  3 
  4 
  5 using namespace std;
  6 const int maxn = 1e5 + 7;
  7 int pre[maxn];
  8 
  9 int Find(int x)
 10 {
 11     int p, tmp;
 12     p = x;
 13     while (x != pre[x])
 14         x = pre[x];
 15     while (p != x)
 16     {
 17         tmp = pre[x];
 18         pre[x] = x;
 19         p = tmp;
 20     }
 21     return x;
 22 }
 23 
 24 void join(int x, int y)
 25 {
 26     int fx = Find(x);
 27     int fy = Find(y);
 28     if (fx != fy)
 29         pre[fx] = fy;
 30 }
 31 
 32 bool Same(int x, int y)
 33 {
 34     return Find(x) == Find(y);
 35 }
 36 
 37 
 38 int m = 4; int n = 8;
 39 
 40 vector<vector<char>> vmap(4, vector<char>(8, '.'));
 41 
 42 void Init()
 43 {
 44     vmap[0][2] = '#';
 45     vmap[0][6] = '*';
 46 
 47     vmap[1][0] = '*';
 48     vmap[1][2] = '#';
 49     vmap[1][4] = 'S';
 50     vmap[1][5] = '#';
 51 
 52     vmap[2][0] = '#';
 53     vmap[2][1] = '#';
 54     vmap[2][2] = '#';
 55     vmap[2][3] = '#';
 56     vmap[2][4] = '#';
 57     vmap[2][5] = '#';
 58 
 59     vmap[3][1] = '*';
 60     vmap[3][4] = '#';
 61     vmap[3][6] = '*';
 62 
 63     for (int i = 0; i < 4; i++) {
 64         for (int j = 0; j < 8; j++) {
 65             cout << vmap[i][j] << " ";
 66         }
 67         cout << endl;
 68     }
 69 
 70     for (int i = 0; i < maxn; i++) {
 71         pre[i] = i;
 72     }
 73          
 74 
 75 }
 76 
 77 int GetId(int x, int y)
 78 {
 79     return (x +1)* 10 + (y+1);
 80 }
 81 
 82 int main()
 83 {
 84     //std::cout << "Hello World!\n"; 
 85     Init();
 86     int myId = -1;
 87     vector<int> record;
 88     for (int i = 0; i < 4; i++) {
 89         for (int j = 0; j < 8; j++) {
 90             if (vmap[i][j] == '#')
 91                 continue;
 92 
 93             if ((i + 1) < 4 && vmap[i+1][j] != '#') {
 94                 int Id = GetId(i, j);
 95                 int Id1 = GetId(i + 1, j);
 96                 join(Id ,Id1);
 97             }
 98             
 99             if ((j + 1) < 8 && vmap[i][j+1] != '#')
100             {
101                 int Id = GetId(i, j);
102                 int Id1 = GetId(i , j+1);
103                 join(Id, Id1);
104 
105             }
106              
107             if ((i - 1) > 0 && vmap[i - 1][j] != '#') {
108                 int Id = GetId(i, j);
109                 int Id1 = GetId(i - 1, j);
110                 join(Id, Id1);
111             
112             }
113             
114             if ((j - 1) > 0 && vmap[i][j - 1] != '#') {
115                 int Id = GetId(i, j);
116                 int Id1 = GetId(i , j-1);
117                 join(Id, Id1);
118             }
119 
120             if (vmap[i][j] == '*') {
121                 record.push_back(GetId(i,j));
122             }
123             else if (vmap[i][j] == 'S') {
124                 myId = GetId(i, j);
125             }
126         }
127     }
128     int count = 0;
129     for (auto& e : record) {
130         if (Same(e, myId)) {
131             count++;
132         }
133     }
134     cout << count;
135 }

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