제출 #283430

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
283430		Atill83	Pipes (BOI13_pipes)	C++14	100 / 100	263 ms	27384 KiB

pipes

#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 5e5+5;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll n, m;
pii edg[MAXN];
int c[MAXN];
vector<pii> adj[MAXN];
int sz[MAXN];
ll ans[MAXN];
bool vis[MAXN];
int remd;
void dfs(int v){
    sz[v]--;
    for(pii j: adj[v]){
        //cerr<<v<<" "<<j.ff<<endl;
        if(sz[j.ff] <= 0) continue;
        ans[j.ss] = 2*c[v];
        c[j.ff] -= c[v];
        c[v] = 0;
        sz[j.ff]--;
        remd--;
        if(sz[j.ff] == 1){
            dfs(j.ff);
        }
    }
}



int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);

    #ifdef Local
        freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/int.txt","r",stdin);
        freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/out.txt","w",stdout);
    #endif

    cin>>n>>m;
    remd = m;

    for(int i = 0; i < n; i++){
        cin>>c[i + 1];
    }
    if(n == 2){
        if(c[1] == c[2]){
            cout<<c[1]<<endl;
        }else{
            cout<<0<<endl;
        }
        return 0;
    }
    for(int i = 0; i < m; i++){
        int a, b;
        cin>>a>>b;
        adj[a].push_back({b, i});
        adj[b].push_back({a, i});
        sz[a]++;
        sz[b]++;
    }

    for(int i = 1; i <= n; i++){
        if(sz[i] == 1){
            //cout<<i<<endl;
            dfs(i);
        }
    }
    int kal = 0;
    int bir = -1;
    for(int i = 1; i <= n; i++){
        //cout<<c[i]<<" ";
        if(sz[i]){
            kal++;
            bir = i;
        }
    }
    //cout<<endl<<kal<<endl;
    //cerr<<kal<<endl;
    if(kal == 0){
        bool tru = 1;
        for(int i = 1; i <= n; i++){
            tru = (tru && c[i] == 0);
        }
        if(tru){
            for(int i = 0; i < m; i++){
                cout<<ans[i]<<endl;
            }
        }else{
            cout<<0<<endl;
        }
    }else if(remd > kal || kal % 2 == 0){
        cout<<0<<endl;
    }else{

        int cur = bir;
        for(pii j: adj[cur]){
            if(sz[j.ff] != 0){
               cur = j.ff; 
            }
        }
        int idx = 0;
        int top = 0, last = -1;
        while(cur != bir){
            if(idx % 2){
                top -= c[cur];
            }else{
                top += c[cur];
            }
            idx++;
            
            for(pii nx: adj[cur]){
                if(nx.ff == last) continue;
                if(sz[nx.ff] > 0){
                    last = cur;
                    cur = nx.ff;
                
                    break;
                }
            }
        }
        //cerr<<top<<endl;
        for(pii j: adj[bir]){
            if(j.ff == last) continue; 
            if(sz[j.ff] > 0){
                if((top +c[bir] ) % 2 != 0){
                    cout<<0<<endl;
                    return 0;
                }
               int deg = (top + c[bir]) / 2;
               ans[j.ss] = 2*deg;
               cur = j.ff;
               c[j.ff] -= deg;
               break;
            }
        }
        last = bir;
        while(cur != bir){
            for(pii nx: adj[cur]){
                if(nx.ff == last) continue;
                if(sz[nx.ff] > 0){
                    ans[nx.ss] = 2*c[cur];
                    c[nx.ff] -= c[cur];
                    last = cur;
                    cur = nx.ff;

                    break;
                }
            }
        }
        for(int i = 1; i <= m; i++){
            cout<<ans[i - 1]<<endl;
        }
    }


    

    #ifdef Local
        cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70