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답안 #505073

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
505073 2022-01-10T13:01:05 Z tgbegimx Dynamite (POI11_dyn) C++17
100 / 100
 1341 ms 37856 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;
int read()
{
    int s=0,f=1;
    char ch=getchar();
    for(;ch<'0'||ch>'9';f=(ch=='-')?-1:f,ch=getchar());
    for(;ch>='0'&&ch<='9';s=s*10+(ch^48),ch=getchar());
    return s*f;
}
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;return;}
        }
        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()
{
    n=read(),m=read();
    d.resize(n+1);
    ke.resize(n+1);
    foru(i,1,n) d[i]=read();
    foru(i,1,n-1)
    {
        int u,v;
        u=read(),v=read();
        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;
    }
    printf("%d",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:33:36: warning: statement has no effect [-Wunused-value]
   33 |         if(kt[v]==-1||dem>m) {kt[u]==-1;return;}
      |                               ~~~~~^~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 296 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 304 KB Output is correct
4 Correct 0 ms 204 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 300 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 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

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 304 KB Output is correct
2 Correct 1 ms 332 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 1088 KB Output is correct
2 Correct 19 ms 2188 KB Output is correct
3 Correct 19 ms 2612 KB Output is correct
4 Correct 31 ms 4684 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 37 ms 4536 KB Output is correct
2 Correct 57 ms 6064 KB Output is correct
3 Correct 100 ms 6744 KB Output is correct
4 Correct 106 ms 10084 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 100 ms 8520 KB Output is correct
2 Correct 120 ms 8624 KB Output is correct
3 Correct 130 ms 8348 KB Output is correct
4 Correct 260 ms 14756 KB Output is correct

Subtask #8
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 510 ms 16812 KB Output is correct
2 Correct 582 ms 19680 KB Output is correct
3 Correct 1043 ms 29576 KB Output is correct
4 Correct 1031 ms 29568 KB Output is correct

Subtask #9
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1320 ms 27888 KB Output is correct
2 Correct 863 ms 25652 KB Output is correct
3 Correct 1231 ms 31200 KB Output is correct

Subtask #10
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1193 ms 35372 KB Output is correct
2 Correct 775 ms 25640 KB Output is correct
3 Correct 1341 ms 37856 KB Output is correct
4 Correct 358 ms 26004 KB Output is correct