oj.uz

Submission #1116646

# Submission time Handle Problem Language Result Execution time Memory
1116646 2024-11-22T03:24:16 Z son2008 Lampice (COCI19_lampice) C++14
42 / 110
 5000 ms 175244 KB 
#include<bits/stdc++.h>
using namespace std;
#define task "noel"
#define ii pair<int,int>
#define fi first
#define se second
//#define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define fii fi.fi
#define fis fi.se3
#define sfi se.fi
#define see se.se
#define base 29
int dx[]={0LL,0LL,1,-1,1,1,-1,-1};
int dy[]={1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=5e4+1;
const int mod=1e9+7;
int h[maxn],n;
char s[maxn];
vector<int>a[maxn];
void dfs(int u,int cha)
{
    for(int v:a[u])
    {
        if(v==cha)continue;
        h[v]=h[u]+1;
        dfs(v,u);
    }
}
namespace sub2
{
    ll h[50068],p[50068],hr[50068];
    ll getl(ll l,ll r){
	return (h[r]-h[l-1]*p[r-l+1]%mod+mod)%mod;
    }
    ll getr(ll i, ll j) {
    return (hr[i] - hr[j+1] * p[j-i+1]%mod+mod)%mod;
    }
    bool check(ll i,ll j){
    return (getl(i,j)==getr(i,j));
    }
    void solve(void)
    {
        p[0]=1;
	for(ll i=1;i<=n;i++){
		h[i]=(h[i-1]*base+s[i]-'a'+1)%mod;
        p[i]=(p[i-1]*base)%mod;
	}
	for(int i=n;i>=1;i--)
	hr[i]=(hr[i+1]*base+s[i]-'a'+1)%mod;
	int ans=0;
	for(int i=1;i<=n;i++){
        int l=0,r=min(n-i,i);
        while(l<=r){
            int mid=(l+r)/2;
            if(check(i-mid+1,i+mid)){
                ans=max(ans,mid*2);
                l=mid+1;
            }
            else
                r=mid-1;
        }
        l=0,r=min(i-1,n-i);
        while(l<=r){
            int mid=(l+r)/2;
            if(check(i-mid,i+mid)){
                ans=max(ans,mid*2+1);
                l=mid+1;
            }
            else
                r=mid-1;
        }
	}
	cout<<ans;
    }
}
namespace sub1
{
    int ans=1,goc;
    int D_odd[maxn],D_even[maxn];
    void Calc_D_odd(string S) {
    int N=S.size();
    S=" "+S;
    int L = 1;
    int R = 0;
    for(int i = 1 ; i <= N ; i++) {
        if(i > R) D_odd[i] = 0;
        else D_odd[i] = min(R - i, D_odd[L + (R - i)]);
        while(i - D_odd[i] - 1 > 0 && i + D_odd[i] + 1 <= N && S[i - D_odd[i] - 1] == S[i + D_odd[i] + 1]) {
            D_odd[i]++;
        }

        if(i + D_odd[i] > R) {
            R = i + D_odd[i];
            L = i - D_odd[i];
        }
    }
}

void Calc_D_even(string S) {
    int N=S.size();
    S=" "+S;
    int L = 1;
    int R = 0;
    for(int i = 1 ; i < N ; i++) {
        int j = i + 1;
        if(j > R) D_even[i] = 0;
        else D_even[i] = min(R - j + 1, D_even[L + (R - j)]);
        while(i - D_even[i] > 0 && j + D_even[i] <= N && S[i - D_even[i]] == S[j + D_even[i]]) {
            D_even[i]++;
        }
        if(i + D_even[i] > R) {
            R = i + D_even[i];
            L = j - D_even[i];
        }
    }
}
    void manacher(string S)
    {
        Calc_D_even(S);
        Calc_D_odd(S);
        int N=S.size();
        for(int i=1;i<N;i++)
        {
            ans=max({ans,D_even[i]*2,D_odd[i]*2+1});
        }
    }
    void dfs(int u,int cha,string tmp)
    {
        tmp+=s[u];
        if(a[u].size()==1&&u!=goc)
            manacher(tmp);
        for(int v:a[u])
        {
            if(v==cha)continue;
            dfs(v,u,tmp);
        }
    }
    void solve(void)
    {
        for(int i=1;i<=n;i++)
        {
            goc=i;
            dfs(i,-1,"");
        }
        cout<<ans;
    }
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    if(fopen(task".inp","r")){
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);}
    cin>>n;
    for(int i=1;i<=n;i++)cin>>s[i];
    for(int i=1;i<n;i++)
    {
        int u,v;
        cin>>u>>v;
        a[u].push_back(v);
        a[v].push_back(u);
    }
    dfs(1,-1);
    if(h[n]==n-1)sub2::solve();
    else sub1::solve();
    cerr <<endl<< "TIME : " << clock() * 0.001 << "s" << endl ;
}

Compilation message

lampice.cpp: In function 'int main()':
lampice.cpp:158:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  158 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
lampice.cpp:159:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  159 |     freopen(task".out","w",stdout);}
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 2896 KB Output is correct
2 Correct 73 ms 3068 KB Output is correct
3 Correct 581 ms 3136 KB Output is correct
4 Correct 1884 ms 3200 KB Output is correct
5 Correct 1 ms 2896 KB Output is correct
6 Correct 1 ms 2896 KB Output is correct
7 Correct 2 ms 2896 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 6480 KB Output is correct
2 Correct 21 ms 5968 KB Output is correct
3 Correct 20 ms 6156 KB Output is correct
4 Correct 22 ms 6736 KB Output is correct
5 Correct 23 ms 6484 KB Output is correct
6 Correct 23 ms 6512 KB Output is correct

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5021 ms 175244 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 2896 KB Output is correct
2 Correct 73 ms 3068 KB Output is correct
3 Correct 581 ms 3136 KB Output is correct
4 Correct 1884 ms 3200 KB Output is correct
5 Correct 1 ms 2896 KB Output is correct
6 Correct 1 ms 2896 KB Output is correct
7 Correct 2 ms 2896 KB Output is correct
8 Correct 22 ms 6480 KB Output is correct
9 Correct 21 ms 5968 KB Output is correct
10 Correct 20 ms 6156 KB Output is correct
11 Correct 22 ms 6736 KB Output is correct
12 Correct 23 ms 6484 KB Output is correct
13 Correct 23 ms 6512 KB Output is correct
14 Execution timed out 5021 ms 175244 KB Time limit exceeded
15 Halted 0 ms 0 KB -