HDU 1195 Open the Lock BFS
简单BFS? 感觉不是很好写,不过我觉得我这种写法还是比较飘逸的。
#include <cstdio> #include <cstring> #include <iostream> #include <map> #include <set> #include <vector> #include <string> #include <queue> #include <deque> #include <bitset> #include <list> #include <cstdlib> #include <climits> #include <cmath> #include <ctime> #include <algorithm> #include <stack> #include <sstream> #include <numeric> #include <fstream> #include <functional> using namespace std; #define MP make_pair #define PB push_back typedef long long LL; typedef unsigned long long ULL; typedef vector<int> VI; typedef pair<int,int> pii; const int INF = INT_MAX / 3; const double eps = 1e-8; const LL LINF = 1e17; const double DINF = 1e60; const int maxn = 10; int d[maxn][maxn][maxn][maxn]; struct Node { int v[4],dist; Node(int a[4],int dd):dist(dd) { for(int i = 0;i < 4;i++) v[i] = a[i]; } }; bool insert(Node &node,int val) { int &vv = d[node.v[0]][node.v[1]][node.v[2]][node.v[3]]; if(vv <= val) return false; vv = val; return true; } Node opr(Node node,int pos,int val) { node.v[pos] += val; if(node.v[pos] == 0) node.v[pos] = 9; if(node.v[pos] == 10) node.v[pos] = 1; return node; } void bfs(int a[4],int b[4]) { memset(d,0x7f,sizeof(d)); queue<Node> q; q.push(Node(a,0)); while(!q.empty()) { Node now = q.front(); q.pop(); for(int i = 0;i < 4;i++) { for(int j = -1;j <= 1;j += 2) { Node nn = opr(now,i,j); if(insert(nn,now.dist + 1)) { q.push(Node(nn.v,now.dist + 1)); } if(i + j < 0 || i + j >= 4) continue; Node nn1 = now; swap(nn1.v[i],nn1.v[i + j]); if(insert(nn1,now.dist + 1)) { q.push(Node(nn1.v,now.dist + 1)); } } } } } int main() { int T; scanf("%d",&T); while(T--) { int tv[2][4]; for(int i = 0;i < 2;i++) { for(int j = 0;j < 4;j++) scanf("%1d",&tv[i][j]); } bfs(tv[0],tv[1]); printf("%d\n",d[tv[1][0]][tv[1][1]][tv[1][2]][tv[1][3]]); } return 0; }