[SOL] #148. 数字格子问题

说实话这题确实挺菜的。。。

废话少说，直接上代码^O^

Code:

 #include <bits/stdc++.h>
 using namespace std;
 inline int read() {
     int x =  , f = ; char ch = getchar();
     for ( ; !isdigit(ch) ; ch = getchar()) if (ch == '-') f = -;
     for ( ; isdigit(ch) ; ch = getchar()) x = x *  + ch - '';
     return x * f;
 }
 const int fac[] = { ,  ,  ,  ,  ,  ,  ,  ,  , };
 const int aim = ;
 const int maxCon = ;
 bool vis[maxCon];
 struct data {
     int con[];
     int hashVal;
     int step;
 }_begin;
 queue <data> Q;
 int Cantor(int s[]) {
     int sum = ;
     for (int i =  ; i <=  ; i ++) {
         int cnt = ;
         for (int j = i +  ; j <=  ; j ++) {
             if (s[i] > s[j]) {
                 cnt ++;
             }
         }
         sum += cnt * fac[ - i];
     }
     return sum + ;
 }
 int bfs() {
     Q.push(_begin);
     while (Q.size()) {
         data _top = Q.front(); Q.pop();

         if (vis[_top.hashVal]) {
             continue;
         }
         if (_top.hashVal == aim) {
             return _top.step;
         }
         vis[_top.hashVal] = true;
         _top.step ++;
         data _next = _top;
         for (int i =  ; i <=  ; i ++) {
             swap(_next.con[i] , _next.con[i + ]);
         }
         _next.hashVal = Cantor(_next.con);
         Q.push(_next);
         _next = _top;
         int _up = _next.con[] , _dwn = _next.con[];
         for (int i =  ; i >=  ; i --) {
             _next.con[i] = _next.con[i - ];
             _next.con[i + ] = _next.con[i + ];
         }
         _next.con[] = _up;
         _next.con[] = _dwn;
         _next.hashVal = Cantor(_next.con);
         Q.push(_next);
         _next = _top;
         int two = _next.con[] , three = _next.con[] , seven = _next.con[] , six = _next.con[];
         _next.con[] = six , _next.con[] = two , _next.con[] = three , _next.con[] = seven;
         _next.hashVal = Cantor(_next.con);
         Q.push(_next);
     }
 }

 int main() {
     for (int i =  ; i <=  ; i ++) {
         _begin.con[i] = read();
     }
     _begin.hashVal = Cantor(_begin.con);
     printf("%d\n" , bfs());
 }