第08讲树

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【POJ2255】Tree Recovery

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

#define N 27

char pre[N];
char in[N];

void PostOrder(int preStart,int preEnd,int inStart,int inEnd)
{
    if( preStart <= preEnd )
    {
        char root = pre[preStart];
        
        int leftLen;
        for( int i=inStart;i<=inEnd;i++ )
        {
            if( root == in[i] )
            {
                leftLen = i - inStart;
                break;
            }
        }

        PostOrder(
            preStart+1,
            preStart + leftLen,
            inStart,
            inStart+leftLen-1
        );
        PostOrder(
            preStart + leftLen+1,
            preEnd,
            inStart + leftLen + 1,
            inEnd
        );

        cout<<root;
    }
}

int main()
{
    while(cin>>pre>>in)
    {        
        PostOrder(0,strlen(pre)-1,0,strlen(in)-1);
        cout<<endl;
    }
    return 1;
}

【ZOJ1167】Trees on the Level

#include <map>
#include <string>
#include <iostream>
#include <stdlib.h>
using namespace std;

class MySort
{
public:
    bool operator ()(const string &_A,const string &_B) const
    {
        if(_A.length() < _B.length() )
            return true;
        if(_A.length()==_B.length() && _A < _B )
            return true;
        return false;
    }
};

map<string,int,MySort> data;

bool InsertNode(string str)
{
    str = str.substr(1,str.length()-2);
    int pos = str.find(',');
    string key = str.substr(pos+1);
    int value = atoi( str.substr(0,pos).c_str() );

    if( data.find(key)!=data.end() )
        return false;
    else
    {
        pair<map<string,int,MySort>::iterator,bool> insertPair;
        insertPair = data.insert( map<string,int,MySort>::value_type(key,value) );
        return insertPair.second;
        //data[key] = value;
        //return true;
    }
}

bool HasRoot()
{
    //cout<<"asdf';
    for(map<string,int,MySort>::iterator i=data.begin();i!=data.end();i++)
    {
        string str = i->first;   

        //cout << ' ' << str.substr(0,str.length()-1) << ' ';

        if( str.length() == 0 )
            continue;
        if( data.find(str.substr(0,str.length()-1)) == data.end() )
            return false;
    }
    return true;
}

int main()
{
    string str;
    bool complete = true;
    while( cin>>str )
    {
        if(str == "()")
        {
            //一个测试结束，给出结论
            if( complete && HasRoot() )
            {
                map<string,int,MySort>::iterator i;
                for( i=data.begin();i!=data.end();i++ )
                {
                    if( i!=data.begin() )
                        cout << ' ';
                    cout << (*i).second ;
                    
                }
            }
            else
            {
                cout << "not complete";
            }

            cout << endl;

            //新测试开始
            //初始化
            data.clear();
            complete = true;
        }
        else
        {
            //加入map
            if( !InsertNode(str) )
                complete = false;
        }
    }
    return 1;
}