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Submission #504047

# Submission time Handle Problem Language Result Execution time Memory
504047 2022-01-09T15:04:11 Z tgbegimx Dynamite (POI11_dyn) C++17
100 / 100
 1298 ms 33412 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=3e5+10;
vector<int> d;
vector<vector<int>> ke;
int dp[N],dem,kt[N];
int n,m;
void dfs(int k,int u,int fa)
{
    int mx1=-1e9,mx2=-1e9;
    if(d[u]) mx1=0;
    //if(k>m) return;
    for(auto v:ke[u])
    {
        if(v==fa) continue;
        //cout<<v<<' ';
        dfs(k,v,u);
        if(kt[v]==1) mx1=max(mx1,dp[v]+1);
        if(kt[v]==2) mx2=max(mx2,dp[v]-1);
        if(kt[v]==-1||dem>m) {kt[u]==-1;return;}
    }
    if(mx1>mx2)
    {
        if(mx1>=k)
        {
          ++dem;
          kt[u]=2;
          dp[u]=k;
          if(dem>m) kt[u]=-1;
        }
        else kt[u]=1,dp[u]=mx1;
    }
    else kt[u]=2,dp[u]=mx2;

}
bool check(int k)
{
    dem=0;
    dfs(k,1,-1);
    if(kt[1]==-1) return 0;
    if(kt[1]==1&&dp[1]>=0) ++dem;
    return dem<=m;
}
void solve()
{
    cin>>n>>m;
    d.resize(n+1);
    ke.resize(n+1);
    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,ans=0;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        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;
    solve();

}

Compilation message

dyn.cpp: In function 'void dfs(int, int, int)':
dyn.cpp:25:36: warning: statement has no effect [-Wunused-value]
   25 |         if(kt[v]==-1||dem>m) {kt[u]==-1;return;}
      |                               ~~~~~^~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 284 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 972 KB Output is correct
2 Correct 26 ms 1876 KB Output is correct
3 Correct 24 ms 2252 KB Output is correct
4 Correct 38 ms 4388 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 3916 KB Output is correct
2 Correct 68 ms 5196 KB Output is correct
3 Correct 179 ms 5692 KB Output is correct
4 Correct 137 ms 9084 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 7200 KB Output is correct
2 Correct 128 ms 7300 KB Output is correct
3 Correct 207 ms 7004 KB Output is correct
4 Correct 290 ms 13280 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 497 ms 13964 KB Output is correct
2 Correct 585 ms 16364 KB Output is correct
3 Correct 990 ms 25900 KB Output is correct
4 Correct 1025 ms 25924 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1230 ms 23436 KB Output is correct
2 Correct 841 ms 21192 KB Output is correct
3 Correct 1210 ms 26752 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1120 ms 31008 KB Output is correct
2 Correct 811 ms 21192 KB Output is correct
3 Correct 1298 ms 33412 KB Output is correct
4 Correct 354 ms 21328 KB Output is correct