Submission #1102249

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102249		alexdd	Graph (BOI20_graph)	C++17	58 / 100	642 ms	19604 KiB

Graph

#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int n,m;
double val[100005];
int u[200005],v[200005],s[200005];
vector<pair<int,int>> con[100005];
bool visited[100005];
bool bun;
double cur;
vector<int> aux;
void dfs(int nod)
{
    cur += abs(val[nod]);
    aux.push_back(nod);
    visited[nod]=1;
    for(auto [adj,sum]:con[nod])
    {
        if(!visited[adj])
        {
            val[adj] = sum - val[nod];
            dfs(adj);
        }
        else if(val[adj] != sum - val[nod])
            bun = 0;
    }
}
vector<double> possible;
int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    for(double i = -40;i<=40;i+=0.5)
        possible.push_back(i);
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        cin>>u[i]>>v[i]>>s[i];
        con[u[i]].push_back({v[i],s[i]});
        con[v[i]].push_back({u[i],s[i]});
    }
    for(int i=1;i<=n;i++)
    {
        visited[i]=0;
    }
    double sum=0;
    for(int i=1;i<=n;i++)
    {
        if(!visited[i])
        {
            double mnm=INF,unde;
            for(double x:possible)
            {
                val[i] = x;
                bun=1;
                aux.clear();
                cur=0;
                dfs(i);
                if(bun && cur<mnm)
                {
                    mnm = cur;
                    unde = x;
                }
                for(int y:aux)
                    visited[y]=0;
            }
            if(mnm==INF)
            {
                cout<<"NO";
                return 0;
            }

            val[i] = unde;
            dfs(i);

            sum += mnm;
        }
    }
    cout<<"YES\n";
    for(int i=1;i<=n;i++)
        cout<<val[i]<<" ";
    return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'int main()':
Graph.cpp:72:20: warning: 'unde' may be used uninitialized in this function [-Wmaybe-uninitialized]
   72 |             val[i] = unde;
      |             ~~~~~~~^~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 0 / 42