[UVA] 704 Colour Hash

所谓“周界搜索”，练习搜索的好题，双向宽搜/迭代加深均可，还有很多细节有待完善，判重有比set更优的结构，宽搜还没写，先存一下。

//Writer:GhostCai && His Yellow Duck

#include<iostream>
#include<string>
#include<set>
#include<queue>
using namespace std;

set<string> book;
set<string> ans;
bool flag;
string tar="034305650121078709X90";
string st,tmp,sr;
int n;

void change(int way,string &r){
    char sav;
    int i;
    switch(way){
        case 1:
            sav=r[11];
            for(i=11;i>=1;i--) r[i]=r[i-1];
            r[0]=sav;
            break;
        case 2:
            sav=r[0];
            for(i=0;i<=10;i++) r[i]=r[i+1];
            r[11]=sav;
            break;
        case 3:
            sav=r[9];
            for(i=9;i<=19;i++) r[i]=r[i+1];
            r[20]=sav;
            break;
        case 4:
            sav=r[20];
            for(i=20;i>=10;i--) r[i]=r[i-1];
            r[9]=sav;
            break;
    }

}

void make(int dp,int mxdp){
    if(dp>mxdp) return;
    cout<<tar<<endl;
    string pre;
    for(int i=1;i<=4;i++){
        pre=tar;
        change(i,tar);
        if(!ans.count(tar)) {
            ans.insert(tar);
            make(dp+1,mxdp);
        }
        tar=pre;
    }
}

void dfs(int dp,int mxdp){
    if(dp>mxdp) return;
    if(flag) return;
    if(ans.count(tmp)){
        flag=1;
        return;
    }
    if(book.count(tmp) ) return;
//  cout<<tmp<<endl;
    int i;
    string pre;
    for(i=1;i<=4;i++){
        pre=tmp;
        change(i,tmp);

//
            dfs(dp+1,mxdp);
            book.insert(tmp); 

        tmp=pre;
    }
}

bool read_s(){
    int s;
    for(int i=1;i<=24;i++){
        cin>>s;
        if(i>=22) continue;
        if(s==10) st+='X' ;
        else st+=char('0'+s);
    }
    return true;
}

int main(){
    make(1,8);
    cin>>n;
    for(int i=1;i<=n;i++){
//      read_s();
        cin>>st;
//      cout<<st<<endl;
        if(st==tar) {
            cout<<"PUZZLE ALREADY SOLVED\n";
            st="";
            continue;
        }
        tmp=st;
        flag=0;
        for(int i=1;i<=8;i++){
            dfs(1,i);
            if(flag){
                cout<<i<<endl;
                break;
            }
        }
        if(!flag) cout<<"NO SOLUTION WAS FOUND IN 16 STEPS\n";
        st="";
    }

}