Submission #936484

#	Time	Username	Problem	Language	Result	Execution time	Memory
936484		GrindMachine	Prisoner Challenge (IOI22_prison)	C++17	100 / 100	9 ms	1892 KiB

prison

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://youtu.be/RwrBLp8AvJA?t=17698
edi

*/

const int MOD = 1e9 + 7;
const int N = 6e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "prison.h"

vector<int> dp(N,inf1), best(N);
int ptr = 1;
vector<vector<int>> ans;
map<int,int> mp[25];
int n;

void go(int l, int r, int p, int d, int bag){
    if(l > r) return;
    ans[p][0] = bag;

    int len = r-l+1;
    if(len <= 2){
        return;
    }

    int segs = best[len];
    int seg_len = (len-2)/segs;

    int curr = l+1;
    int seg = 1;

    while(curr < r){
        if(!mp[d].count(seg)){
            mp[d][seg] = ptr++;
        }
        int nxt = mp[d][seg];
        for(int j = curr; j <= curr+seg_len-1; ++j){
            ans[p][j] = nxt;
        }

        for(int j = l; j <= curr; ++j){
            ans[nxt][j] = -((bag^1)+1);
        }
        for(int j = curr+seg_len-1; j <= r; ++j){
            ans[nxt][j] = -(bag+1);
        }

        go(curr,curr+seg_len-1,nxt,d+1,bag^1);
        curr += seg_len;
        seg++;
    }
}

vector<vector<int>> devise_strategy(int n_) {
    n = n_;

    dp[0] = dp[1] = dp[2] = 0;
    for(int i = 3; i < N; ++i){
        rep1(j,min(i-2,20)){
            int val = j+dp[ceil2(i-2,j)];
            if(val < dp[i]){
                best[i] = j;
                dp[i] = val;
            }
        }
    }

    int mx_val = -1;
    rep(i,N){
        if(dp[i] <= 20){
            mx_val = i;
        }
    }

    ans = vector<vector<int>>(21,vector<int>(mx_val+1));
    ans[0][1] = -1;
    ans[0][mx_val] = -2;
    go(1,mx_val,0,0,0);

    rep(i,21){
        while(sz(ans[i]) > n+1){
            ans[i].pop_back();
        }
    }

    // rep(i,sz(ans)){
    //     rep(j,n+1){
    //         cout << ans[i][j] << " ";
    //     }
    //     cout << endl;
    // }

    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 90 / 90