제출 #1030634

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1030634		ttamx	Graph (BOI20_graph)	C++17	100 / 100	91 ms	25392 KiB

Graph

#include<bits/stdc++.h>

using namespace std;

using db = double;

const int N=1e5+5;

int n,m;
vector<int> adj[N];
bool vis[N];
int a[N],b[N],ans[N];


int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n >> m;
    vector<vector<pair<int,int>>> adj(n);
    for(int i=0;i<m;i++){
        int u,v,w;
        cin >> u >> v >> w;
        u--,v--;
        adj[u].emplace_back(v,w);
        adj[v].emplace_back(u,w);
    }
    vector<int> comp;
    pair<int,int> val;
    bool found=false;
    function<void(int)> dfs=[&](int u){
        comp.emplace_back(u);
        vis[u]=true;
        for(auto [v,w]:adj[u]){
            if(!vis[v]){
                a[v]=-a[u];
                b[v]=w-b[u];
                dfs(v);
            }else{
                if(a[u]+a[v]==0){
                    if(b[u]+b[v]!=w){
                        cout << "NO",exit(0);
                    }
                }else{
                    int num=w-b[u]-b[v];
                    int den=a[u]+a[v];
                    if(!found){
                        found=true;
                        val={num,den};
                    }else if(num*val.second!=val.first*den){
                        cout << "NO",exit(0);
                    }
                }
            }
        }
    };
    for(int i=0;i<n;i++)if(!vis[i]){
        comp.clear();
        found=false;
        a[i]=1,b[i]=0;
        dfs(i);
        auto calc=[&](int x){
            int res=0;
            for(auto u:comp){
                res+=abs(a[u]*x+b[u]*2);
            }
            return res;
        };
        auto answer=[&](int x){
            for(auto u:comp){
                ans[u]=a[u]*x+b[u]*2;
            }
        };
        if(found){
            answer(val.first*2/val.second);
        }else{
            int c=comp.size();
            int l=-c*2-1,r=c*2+1;
            while(l<r){
                int m=l+(r-l)/2;
                if(calc(m)<calc(m+1))r=m;
                else l=m+1;
            }
            answer(l);
        }
    }
    cout << "YES\n";
    for(int i=0;i<n;i++)cout << db(ans[i])/2.0 << " ";
}

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 42 / 42