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 }

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