oj.uz

Submission #1116639

# Submission time Handle Problem Language Result Execution time Memory
1116639 2024-11-22T03:03:28 Z son2008 Lampice (COCI19_lampice) C++14
42 / 110
 5000 ms 175128 KB 
#include<bits/stdc++.h>
using namespace std;
#define task "task"
#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
{
    int h[50068],p[50068],hr[50068];
    int getl(int l,int r){
	return (h[r]-h[l-1]*p[r-l+1]%mod+mod)%mod;
    }
    int getr(int i, int j) {
    return (hr[i] - hr[j+1] * p[j-i+1]%mod+mod)%mod;
    }
    bool check(int i,int j){
    return (getl(i,j)==getr(i,j));
    }
    void solve(void)
    {
        p[0]=1;
	for(int 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=0;
    bool check(string s)
    {
        int l=0,r=s.size()-1;
        while(l<r)
        {
            if(s[l]!=s[r])return false;
            l++;
            r--;
        }
        return true;
    }
    bool dfs(int u,int cha,string tmp,int dem)
    {
        tmp+=s[u];
        bool ok=false;
        for(int v:a[u])
        {
            if(v==cha)continue;
            if(dfs(v,u,tmp,dem+1))ok=true;
        }
        if(ok)return true;
        else
        {
            if(ans>=dem)return true;
            else if(check(tmp))
            {
                ans=dem;
                return true;
            }
            else return false;
        }
    }
    void solve(void)
    {
        for(int i=1;i<=n;i++)
        {
            dfs(i,-1,"",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:130:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
lampice.cpp:131:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |     freopen(task".out","w",stdout);}
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2640 KB Output is correct
2 Correct 11 ms 2640 KB Output is correct
3 Correct 154 ms 2640 KB Output is correct
4 Correct 300 ms 2812 KB Output is correct
5 Correct 1 ms 2640 KB Output is correct
6 Correct 1 ms 2640 KB Output is correct
7 Correct 1 ms 2640 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 5880 KB Output is correct
2 Correct 18 ms 6396 KB Output is correct
3 Correct 18 ms 6472 KB Output is correct
4 Correct 19 ms 6480 KB Output is correct
5 Correct 20 ms 6736 KB Output is correct
6 Correct 20 ms 6736 KB Output is correct

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5031 ms 175128 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2640 KB Output is correct
2 Correct 11 ms 2640 KB Output is correct
3 Correct 154 ms 2640 KB Output is correct
4 Correct 300 ms 2812 KB Output is correct
5 Correct 1 ms 2640 KB Output is correct
6 Correct 1 ms 2640 KB Output is correct
7 Correct 1 ms 2640 KB Output is correct
8 Correct 17 ms 5880 KB Output is correct
9 Correct 18 ms 6396 KB Output is correct
10 Correct 18 ms 6472 KB Output is correct
11 Correct 19 ms 6480 KB Output is correct
12 Correct 20 ms 6736 KB Output is correct
13 Correct 20 ms 6736 KB Output is correct
14 Execution timed out 5031 ms 175128 KB Time limit exceeded
15 Halted 0 ms 0 KB -