Submission #642770

#	Time	Username	Problem	Language	Result	Execution time	Memory
642770		berr	Graph (BOI20_graph)	C++17	100 / 100	165 ms	28980 KiB

Graph

#include <bits/stdc++.h>
using namespace std;
#define int long long
int c[(int)1e5+5], val[(int)1e5+5], vis[(int)(1e5+5)], val2[(int)(1e5)+5];
vector<array<int, 2>> adj[(int)(1e5+5)];
vector<int> pos[(int)(1e5+5)], aaa;
int flag=1;

void dfs(int x, int y, int z)
{

    vis[x]=z;
    pos[z].push_back(x);
    for(auto i: adj[x])
    {
        if(i[0]==y) continue;
        if(vis[i[0]]!=0)
        {
            if(c[x]+c[i[0]]==0&&val[i[0]]+val[x]!=i[1])
            {
                flag=0;
            }
            else if(c[x]+c[i[0]]!=0)
            {
                if(val2[z]==-1)
                {
                    val2[z]=(i[1]-val[i[0]]-val[x])/(c[x]+c[i[0]]);
                }
                else
                {
                    if(val2[z]!=(i[1]-val[i[0]]-val[x])/(c[x]+c[i[0]])) flag=0;
                }
            }
        }
        else
        {
            val[i[0]]=i[1]-val[x];
            c[i[0]]=-1*c[x];

            dfs(i[0], x, z);
        }
    }
}


void dfs2(int z, int p)
{
    vis[z]=1;
    for(auto i: adj[z])
    {
        if(val[i[0]]+val[z]!=i[1]) flag=0;
        else if(!vis[i[0]]) dfs2(i[0], z);
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(false); cin.tie(0);
    
    int n, m; cin>>n>>m;


    for(int i=0; i<m; i++)
    {
        int x, y, z; cin>>x>>y>>z;

        z*=1e7;
        adj[x].push_back({y, z});
        adj[y].push_back({x, z});
    }

    for(int i=1; i<=n; i++)
    {
        val2[i]=-1;
    }

    for(int i=1; i<=n; i++)
    {
        if(!vis[i])  c[i]=1,dfs(i, 0, i), aaa.push_back(i);
    }


    for(auto z: aaa)
    {
        if(val2[z]!=-1)
        {
            for(auto i: pos[z])
            {
                val[i]+=c[i]*val2[z];
            }
        }
       else
        {
            int s=-1e10;
            for(int i=40; i>=0; i--)
            {
                int tmp=s+(1LL<<i);
         
                int ans1=0,  ans2=0;
 
                int tmp2=tmp-1;
 
                for(auto j: pos[z])
                {
                    ans1+=abs(val[j]+(c[j]*tmp));
                    ans2+=abs(val[j]+(c[j]*tmp2));
                }
 
                if(ans1<ans2) s=tmp; 
            }
 
 
            val2[z]=s;
            for(auto i: pos[z])
            {
                val[i]+=c[i]*val2[z];
            }
        }
    
    }

    if(flag)
    {

        cout<<"YES\n";
        for(int i=1; i<=n; i++)
        {
            float x=(float)val[i]/(float)10000000;
            cout<<fixed<<x<<" ";
        }
    }
    else
    {
        cout<<"NO\n";
    }
}

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