hdu-5012-Xi'an网络赛-1006-水bfs

题意略。

思路：简单的四方向BFS，用map记录去重。

总结：WA了一发因为骰子面的变换写错了一个地方。要细心。

AC代码（Exe.Time: 31ms）：

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <vector>
  4 #include <algorithm>
  5 #include <map>
  6 #include <queue>
  7 using namespace std;
  8
  9 struct node
 10 {
 11     int up, dn, l, r, fr, bk;
 12     int num;
 13     bool operator == (const node x) const
 14     {
 15         bool re =  (up == x.up && dn == x.dn && l == x.l && r == x.r && fr == x.fr && bk == x.bk);
 16         return re;
 17     }
 18     bool operator < (const node x) const
 19     {
 20         if(up == x.up) {
 21             if(dn == x.dn) {
 22                 if(l == x.l) {
 23                     if(r == x.r) {
 24                         return fr < x.fr;
 25                     }
 26                     return r < x.r;
 27                 }
 28                 return l < x.l;
 29             }
 30             return dn < x.dn;
 31         }
 32         return up < x.up;
 33     }
 34 };
 35 void Swap(int &a, int &b)
 36 {
 37     a = a^b;
 38     b = a^b;
 39     a = a^b;
 40 }
 41 node arr, brr;
 42 void change_lr(node &x)
 43 {
 44     Swap(x.l, x.dn);
 45     Swap(x.r, x.up);
 46     Swap(x.l, x.r);
 47 }
 48 void change_rr(node &x)
 49 {
 50     Swap(x.up, x.r);
 51     Swap(x.dn, x.l);
 52     Swap(x.up, x.dn);
 53 }
 54 void change_br(node &x)
 55 {
 56     Swap(x.up, x.fr);
 57     Swap(x.dn, x.bk);
 58     Swap(x.fr, x.bk);
 59 }
 60 void change_fr(node &x)
 61 {
 62     Swap(x.up, x.fr);
 63     Swap(x.dn, x.bk);
 64     Swap(x.dn, x.up);
 65 }
 66 void print(node x)
 67 {
 68     cout<<x.up<<" "<<x.dn<<" "<<x.l<<" "<<x.r<<" "<<x.fr<<" "<<x.bk<<endl;
 69 }
 70 void bfs(node cont, int &num)
 71 {
 72     int cnt = 0;
 73     queue<node> q;
 74     map<node, int> vis;
 75     map<node, int>::iterator it;
 76     vis.insert(pair<node, int> (cont, cnt++));
 77     q.push(cont);
 78     while(!q.empty()) {
 79         node fro = q.front(); q.pop();
 80         if(fro == brr) { num = fro.num; return; }
 81         node x;
 82         for(int i = 0; i < 4; i++ ){
 83             x = fro;
 84             x.num = fro.num+1;
 85             if(i == 0) change_br(x);
 86             else if(i == 1) change_fr(x);
 87             else if(i == 2) change_lr(x);
 88             else if(i == 3) change_rr(x);
 89             it = vis.find(x);
 90             if(it == vis.end()) {
 91                 vis.insert(pair<node, int> (x, cnt++));
 92                 q.push(x);
 93             }
 94         }
 95     }
 96     num = -1;
 97 }
 98
 99 int main()
100 {
101     node a;
102     while(scanf("%d%d%d%d%d%d", &a.up, &a.dn, &a.l, &a.r, &a.fr, &a.bk) != EOF) {
103         a.num = 0;
104         arr = a;
105         scanf("%d%d%d%d%d%d", &a.up, &a.dn, &a.l, &a.r, &a.fr, &a.bk);
106         brr = a;
107         int ans;
108         bfs(arr, ans);
109         printf("%d\n", ans);
110     }
111 }

hdu-5012-Xi'an网络赛-1006-水bfs