zoj 2146

   简单广搜...set好用..恩.

#include <cstdio>#include <iostream>#include <queue>#include <set>using namespace std;struct paipai{int num;int step;};queue<struct paipai>q;set<int> used;int a[5],b[5];int T,from,to; void itoa(int n,int a[]){ for(int i=3;i>=0;i--) { a[i] = n%10; n/=10; }}int atoi(int a[]){int sum = 0;for(int i=0;i<4;i++){sum*=10;sum+=a[i];}return sum;}void bfs(){used.clear();used.insert(from);struct paipai now;now.num=from;now.step = 0;while(!q.empty())q.pop();q.push(now);now = q.front();while(!q.empty()){now= q.front();q.pop();if(now.num==to){cout<<now.step<<endl;return ;}now.step++;for(int i=0;i<4;i++){itoa(now.num,a);a[i]+=1;if(a[i]==10)a[i]=1;struct paipai tmp;tmp.num=atoi(a);tmp.step=now.step;if(!used.count(tmp.num)){q.push(tmp);used.insert(tmp.num);}}for(int i=0;i<4;i++){itoa(now.num,a);a[i]-=1;if(a[i]==0)a[i]=9;struct paipai tmp;tmp.num=atoi(a);tmp.step=now.step;if(!used.count(tmp.num)){q.push(tmp);used.insert(tmp.num);}}for(int i=0;i<3;i++){itoa(now.num,a);a[i]^=a[i+1];a[i+1]^=a[i];a[i]^=a[i+1];struct paipai tmp;tmp.num=atoi(a);tmp.step=now.step;if(!used.count(tmp.num)){q.push(tmp);used.insert(tmp.num);}}} }int main(void){cin>>T; T=2; while(T--) { cin>>from>>to; //from = 1234;to = 2144; // from=1111;to=9999; bfs(); }return 0;}