洛谷 P1032 字串变换

P1032 字串变换

#include<iostream>#include<string>#include<map>using namespace std;map<string,bool> map1;string s1,s2;int n,l=1,r=0;int deep[500000];string que[500000];string sa[7];string sb[7];void in(string s,int deep1){    que[++r]=s;    deep[r]=deep1;    map1[s]=true;}void do1(string s,string rule1,string rule2,int deep1){    string sx;    int k=s.find(rule1,0),i;    bool flag;    while(k!=string::npos)    {        flag=false;        sx=s;        sx.erase(k,rule1.length());        sx.insert(k,rule2);        if(sx==s2)        {            cout<<deep1+1;            exit(0);        }        /*for(i=0;i<didnum;i++)            if(did[i]==sx)                flag=true;*/  //此处原来是用did记录所有已搜索到的字串，然后每次遍历did数组判断是否重复，后用map优化        if(map1.count(sx)==0)        {            in(sx,deep1+1);            //cout<<sx<<k<<endl;        }        k=s.find(rule1,k+1);    }}void work(){    int i;    while(l<=r)    {        if(deep[l]>=10)        {            cout<<"NO ANSWER!";            exit(0);        }        for(i=1;i<=n;i++)        {            do1(que[l],sa[i],sb[i],deep[l]);        }        l++;    }}int main(){    int i;    cin>>s1>>s2;    while(cin>>sa[n+1]>>sb[n+1])n++;    in(s1,0);    work();    cout<<"NO ANSWER!";    return 0;}