【例题 6-21 UVA - 506】System Dependencies

/*
    1.Shoud it use long long ?
    2.Have you ever test several sample(at least therr) yourself?
    3.Can you promise that the solution is right? At least,the main ideal
    4.use the puts("") or putchar() or printf and such things?
    5.init the used array or any value?
    6.use error MAX_VALUE?
*/
#include <bits/stdc++.h>
using namespace std;

string s;
map <int,vector <int> > yilai,beiyilai;
map <int,int> status;
map <string,int> dic;
map <int,string> dic2;
vector <int> installed;
string ope;
int tot = 0;

void pd(string temp){
    if (dic[temp]==0) {
        dic[temp] = ++tot;
        dic2[tot] = temp;
    }
}

void ins(int id,bool highest){
    if (status[id]==0){
        if (yilai.find(id)!=yilai.end()){
            vector <int> v = yilai[id];
            int len = v.size();
            for (int i = 0;i < len;i++){
                int x = v[i];
                ins(x,0);               
            }
        }
        cout << "   Installing "<<dic2[id] << endl;
        installed.push_back(id);
        status[id] = (highest?1:2);
    }
}

bool need(int x){
    if (beiyilai.find(x)!=beiyilai.end()){
        vector <int> v = beiyilai[x];
        int len = v.size();
        for (int i = 0;i < len;i++){
            int x = v[i];
            if (status[x]) return true;
        }
    }
    return false;
}

void dele(int id,bool highest){
    if ( !need(id) && (highest || status[id]==2)){
        status[id] = 0;
        cout << "   Removing " << dic2[id] << endl;
        installed.erase(remove(installed.begin(),installed.end(),id),installed.end());
        if (yilai.find(id)!=yilai.end()){
            vector <int> v = yilai[id];
            int len = v.size();
            for (int i = 0;i < len;i++){
                int x = v[i];
                if (status[x]) dele(x,0);               
            }
        }
    }
}

int main(){
    #ifdef LOCAL_DEFINE
        freopen("F:\\c++source\\rush_in.txt", "r", stdin);
    #endif
    ios::sync_with_stdio(0),cin.tie(0);
    
    while (getline(cin,s)){
        yilai.clear(),beiyilai.clear(),     
        status.clear(),dic.clear();dic2.clear();
        installed.clear();
        while (s!="END"){
            cout << s << endl;
            stringstream ss(s);
            ss >> ope;
            if (ope=="INSTALL"){
                string x;
                ss >> x;
                pd(x);
                int y = dic[x]; 
                if (status[y]!=0)
                    cout <<"   "<<x<<" is already installed."<<endl;
                else
                    ins(y,1);
            }else if (ope=="REMOVE"){
                string x;
                ss >> x;
                pd(x);
                int y = dic[x];
                if (status[y]==0)
                    cout <<"   "<<x<<" is not installed."<<endl;
                else if (need(y))
                    cout <<"   "<<x<<" is still needed."<<endl;
                    else{
                        dele(y,1);
                    }
            }else if (ope=="LIST"){
                for (int x:installed){
                    cout <<"   "<<dic2[x]<<endl;
                }
            }else{
                //depend
                string x,y;int xx,yy;
                ss >> x;
                pd(x);xx = dic[x];
                while (ss>>y){
                    pd(y);yy = dic[y];
                    yilai[xx].push_back(yy);
                    beiyilai[yy].push_back(xx);
                }
            }
            getline(cin,s);
        }
        cout << s << endl;
    }

    return 0;
}