【链接】点击打开链接
【题意】
在这里写题意
【题解】
bfs+map
【错的次数】
0
【反思】
在这了写反思
【代码】
#include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <vector> #include <map> #include <queue> #include <iomanip> #include <set> #include <cstdlib> #include <cmath> #include <bitset> using namespace std; #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define LL long long #define rep1(i,a,b) for (int i = a;i <= b;i++) #define rep2(i,a,b) for (int i = a;i >= b;i--) #define mp make_pair #define pb emplace_back #define fi first #define se second #define ld long double #define ms(x,y) memset(x,y,sizeof x) #define ri(x) scanf("%d",&x) #define rl(x) scanf("%lld",&x) #define rs(x) scanf("%s",x) #define rf(x) scnaf("%lf",&x) #define oi(x) printf("%d",x) #define ol(x) printf("%lld",x) #define oc putchar(' ') #define os(x) printf(x) #define all(x) x.begin(),x.end() #define Open() freopen("F:\rush.txt","r",stdin) #define Close() ios::sync_with_stdio(0) #define sz(x) ((int) x.size()) #define ld long double typedef pair<int, int> pii; typedef pair<LL, LL> pll; //mt19937 myrand(time(0)); //int get_rand(int n){return myrand()%n + 1;} const int dx[9] = { 0,1,-1,0,0,-1,-1,1,1 }; const int dy[9] = { 0,0,0,-1,1,-1,1,-1,1 }; const double pi = acos(-1.0); const int N = 10; const int goal = 123456789; char s[N]; int temp,a[4][4]; queue <int> dl; map <int, int> dic; int getnum(int a[4][4]) { int now = 0; rep1(i, 1, 3) rep1(j, 1, 3) now = now * 10 + a[i][j]; return now; } int main() { //Open(); //Close(); while (~rs(s)) { int len = strlen(s); temp = 0; rep1(i, 0, len - 1) temp = temp * 10 + s[i] - '0'; dic.clear(); dl.push(temp); dic[temp] = 1; while (!dl.empty()) { int x = dl.front(); int xx = x; dl.pop(); if (dic[xx] >= 6) continue; rep2(i, 3, 1) rep2(j, 3, 1) { a[i][j] = x % 10; x /= 10; } rep1(i, 1, 3) { rep1(j, 1, 3) { int temp = a[i][1]; rep1(k, 1, 2) a[i][k] = a[i][k + 1]; a[i][3] = temp; if (j == 3) continue; temp = getnum(a); if (dic[temp] == 0) { dic[temp] = dic[xx] + 1; dl.push(temp); } } } rep1(i, 1, 3) { rep1(j, 1, 3) { int temp = a[1][i]; rep1(k, 1, 2) a[k][i] = a[k + 1][i]; a[3][i] = temp; if (j == 3) continue; temp = getnum(a); if (dic[temp] == 0) { dic[temp] = dic[xx] + 1; dl.push(temp); } } } } if (dic[goal] == 0) { puts("impossible"); } else { oi(dic[goal] - 1); puts(""); } } return 0; }