| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 840769 | MohamedAliSaidane | Closing Time (IOI23_closing) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "closing.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define ff first
#define ss second
#define all(x) (x).begin(),(x).end()
const int nax = 505;
const ll INF = 1e18 + 5;
int n, x, y;
ll k;
vector<pair<int,ll>> A[nax];
vector<int> adj[nax];
ll dx[nax], dy[nax];
ll dp[nax][2 * nax][4], memo[nax][2 * nax][4][nax];
int tx[nax], ty[nax];
void dfsx(int u, int par)
{
for(auto e: A[u])
{
if(e.ff == par)
continue;
dx[e.ff] = dx[u] + e.ss;
tx[e.ff] = u;
dfsx(e.ff, u);
}
}
void dfsy(int u, int par)
{
for(auto e: A[u])
{
if(e.ff == par)
continue;
dy[e.ff] = dy[u] + e.ss;
ty[e.ff] = u;
dfsy(e.ff, u);
}
}
ll f(int u, int ans, int typ);
ll g(int u, int rem, int typ, int idx)
{
if(rem < 0)
return INF;
if(idx == (int)(adj[u].size()))
return rem > 0? INF: 0ll;
if(memo[u][rem][typ][idx] != -1)
return memo[u][rem][typ][idx];
if(rem == 0)
return memo[u][rem][typ][idx] = 0ll;
ll rep = INF;
for(int j = 0; j <= rem; j++)
{
if(typ == 0)
{
if(adj[u][idx] == ty[u])
rep = min(rep, g(u, rem-j, typ, idx + 1) + f(adj[u][idx], j - 1, 2));
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j, 0));
}
else if(typ == 1)
{
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 1, 1));
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j, 0));
if(ty[u] == adj[u][idx])
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 2, 2));
}
else if(typ == 2)
{
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 1, 2));
if(ty[u] != adj[u][idx])
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j, 0));
}
else
{
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 2, 3));
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 1, 2));
if(ty[u] != adj[u][idx])
{
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j - 1, 1));
rep = min(rep, g(u, rem - j, typ, idx + 1) + f(adj[u][idx], j, 0));
}
}
}
return memo[u][rem][typ][idx] = rep;
}
ll f(int u, int ans, int typ)
{
if(ans < 0)
return INF;
if(dp[u][ans][typ] != -1)
return dp[u][ans][typ];
ll deplt = typ == 0? 0: typ == 1? dx[u]: typ == 2? dy[u]: max(dx[u], dy[u]);
if(adj[u].empty())
return dp[u][ans][typ] = ans > 0? INF: deplt;
return dp[u][ans][typ] = g(u, ans, typ, 0) + deplt;
}
int max_score(int N, int X, int Y, long long K,
std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
n = N, x = X, y = Y, k = K;
for(int i = 0; i < N; i ++)
{
A[i].clear();
adj[i].clear();
for(int ans = 0; ans <= 2 * N; ans++)
{
for(int t = 0; t < 4; t++)
dp[i][ans][t] = -1;
}
}
for(int i = 0 ; i < N; i++)
{
for(int j= 0; j <= 2 * N; j++)
{
for(int typ = 0; typ < 4; typ++)
{
for(int idx = 0; idx < N; idx++)
memo[i][j][typ][idx] = -1;
}
}
}
for(int i = 0; i < n - 1; i++)
{
A[U[i]].pb({V[i], W[i]});
A[V[i]].pb({U[i], W[i]});
}
tx[x] = x, ty[y] = y;
dx[x] = dy[y] = 0ll;
dfsx(x, x);
dfsy(y, y);
for(int i = 0; i < n; i++)
{
vector<int> v;
for(auto e: A[i])
if(e.ff != tx[i])
adj[i].pb(e.ff);
}
for(int ans = 2; ans <= 2 * n; ans++)
{
ll cost = INF;
cost = min(cost, f(x, ans, 0));
cost = min(cost, f(x, ans - 1, 1));
cost = min(cost, f(x, ans - 1, 2));
cost = min(cost, f(x, ans - 2, 3));
if(cost > k)
return ans - 1;
}
return 2 * n;
}