Submission #1144299

#	Time	Username	Problem	Language	Result	Execution time	Memory
1144299		Noproblem29	Giraffes (JOI22_giraffes)	C++20	59 / 100	618 ms	632 KiB

giraffes

#include<bits/stdc++.h>
using namespace std;
#ifndef BADGNU
#pragma GCC target("sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#endif
#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> 
using namespace __gnu_pbds;
#define ll long long
#define int ll
#define ld long double
#define y1 cheza
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<class T> using ordered_multiset = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;
const int N=305;
const int M=5001;
const int B=447;
const int mod=998244353;
const ll INF=2e9;
const int dx[]={1,-1,0,0};
const int dy[]={0,0,1,-1};
const double eps=1e-6;
int n;
int p[N];
int a[N];
int dp[4][N];
void test(){
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>p[i];
        p[i]--;
    }
    int ans=n-1;
    while(1){
        vector<tuple<int,int,int>>v;
        for(int mask=0;mask<4;mask++){
            for(int i=0;i<n;i++){
                if(dp[mask][i]!=INF){
                    int x=i-(mask&2?dp[mask][i]:0);
                    int y=p[i]-(mask&1?dp[mask][i]:0);
                    v.push_back({x,y,dp[mask][i]});
                }
            }
        }
        bool ok=1;
        for(int mask=0;mask<4;mask++){
            for(int i=0;i<n;i++){
                dp[mask][i]=INF;
                int cur=INF;
                for(auto [x,y,w]:v){
                    x=(mask&2?i-(x+w):x-i);
                    y=(mask&1?p[i]-(y+w):y-p[i]);
                    if(x>0&&y>0){
                        cur=min(cur,max(x,y)+w);
                    }
                }
                int lx=(mask&2?i:(n-1)-i);
                int rx=(mask&1?p[i]:(n-1)-p[i]);
                if(cur<=min(lx,rx)){
                    dp[mask][i]=cur;
                }
                if(dp[mask][i]!=INF){
                    ok=0;
                }
            }
        }
        if(ok)break;
        ans--;
    }
    cout<<ans<<'\n';

}



/*

*/
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    // cout.tie(nullptr);
    int t2=1;
    // cin>>t2;
    for(int i=1;i<=t2;i++){
        test();
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 22 / 22
• Subtask 3: 27 / 27
• Subtask 4: 0 / 41