Submission #504022

# Submission time Handle Problem Language Result Execution time Memory
504022 2022-01-09T14:21:30 Z tgbegimx Dynamite (POI11_dyn) C++17
70 / 100
578 ms 41148 KB
#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0) ; cin.tie(0);cout.tie(0)
#define ll long long
#define foru(i,l,r) for(int i=l;i<=r;i++)
#define ford(i,l,r) for(int i=l;i>=r;i--)
#define pb push_back
using namespace std;
const int N=2e5+10;
vector<int> d;
vector<vector<int>> ke;
int f[N],num,kt[N];
int n,m;
void dfs(int k,int u,int fa)
{
    int mx1=-1e9,mx2=-1e9;
    if(d[u]) mx1=0;
    for(auto v:ke[u])
    if(v!=fa)
    {
        //cout<<v<<' ';
        dfs(k,v,u);
        if(kt[v]==1) mx1=max(mx1,f[v]+1);
        if(kt[v]==2) mx2=max(mx2,f[v]-1);
    }
    if(mx1>mx2)
    {
        if(mx1>=k)
        {
          ++num,kt[u]=2,f[u]=k;
          if(num>m) kt[u]=-1;
        }
        else kt[u]=1,f[u]=mx1;
    }
    else kt[u]=2,f[u]=mx2;

}
bool check(int k)
{
    num=0;
    dfs(k,1,-1);
    //cout<<'\n';
    if(kt[1]==-1) return 0;
    if(kt[1]==1&&f[1]>=0) ++num;
    return num<=m;
}
void solve()
{
    cin>>n>>m;
    d.resize(n+1);
    ke.resize(n+5);
    foru(i,1,n) cin>>d[i];
    foru(i,1,n-1)
    {
        int u,v;
        cin>>u>>v;
        ke[u].pb(v);
        ke[v].pb(u);
    }
    //for(auto v:ke[5]) cout<<v<<' ';
    int l=0,r=n;
    int ans=0;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        //cout<<check(mid)<<' ';
        if(check(mid)) ans=mid,r=mid-1;
        else l=mid+1;
    }
    cout<<ans;
}
int main()
{
    //freopen("main.inp","r",stdin);
    //freopen("main.out","w",stdout);
    fast;
    int t=1;
    //cin>>t;
    while(t--)
       solve();

}
# Verdict Execution time Memory Grader output
1 Correct 1 ms 208 KB Output is correct
2 Correct 0 ms 320 KB Output is correct
3 Correct 0 ms 324 KB Output is correct
4 Correct 0 ms 320 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 304 KB Output is correct
2 Correct 1 ms 300 KB Output is correct
3 Correct 0 ms 208 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 316 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 7 ms 1104 KB Output is correct
2 Correct 22 ms 2120 KB Output is correct
3 Correct 26 ms 2656 KB Output is correct
4 Correct 31 ms 4708 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 36 ms 4504 KB Output is correct
2 Correct 76 ms 6152 KB Output is correct
3 Correct 102 ms 6736 KB Output is correct
4 Correct 128 ms 10104 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 173 ms 8652 KB Output is correct
2 Correct 121 ms 8540 KB Output is correct
3 Correct 198 ms 8360 KB Output is correct
4 Correct 261 ms 14800 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 578 ms 16872 KB Output is correct
2 Runtime error 136 ms 32844 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 166 ms 41148 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 167 ms 40632 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -