제출 #380402

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
380402		Fidisk	Building 4 (JOI20_building4)	C++14	11 / 100	178 ms	268012 KiB

building4

#include <bits/stdc++.h>
using namespace std;

#define oo 1e15
#define fi first
#define se second
#define sp(iiii) setprecision(iiii)
#define IO ios_base::sync_with_stdio(false); cin.tie(0)
#define ms(aaaa,xxxx) memset(aaaa,xxxx,sizeof(aaaa))
#define cntbit(xxxx) __builtin_popcount(xxxx)
#define getbit(xxxx,aaaa) ((xxxx>>(aaaa-1))&1)

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<pair<int,int>,int> piii;
typedef pair<long long,long long> pll;
typedef pair<pair<long long,long long>,long long> plll;
typedef pair<pair<long long,long long>,pair<long long,long long>> pllll;
typedef pair<pair<long long,long long>,bool> pllb;

const ll base=361;
const ll mod=1e9+7;
const ld eps=1e-5;
const ll maxn=1e7-1;

ll n,i,a[500009],b[500009],f[5009][5009][4],j;

void Trace(ll x,ll y,ll msk) {
    if (x==0) {
        return;
    }
    if (msk==1) {
        if (f[x-1][y-1][0]&&b[x]>=a[x-1]) {
            Trace(x-1,y-1,0);
        }
        else {
            Trace(x-1,y-1,1);
        }
        cout<<'B';
    }
    else {
        if (f[x-1][y][0]&&a[x]>=a[x-1]) {
            Trace(x-1,y,0);
        }
        else {
            Trace(x-1,y,1);
        }
        cout<<'A';
    }
}

int main(){
    IO;
    cin>>n;
    for (i=1;i<=2*n;i++) {
        cin>>a[i];
    }
    for (i=1;i<=2*n;i++) {
        cin>>b[i];
    }
    if (n<=2000) {
        f[0][0][1]=true;
        f[0][0][0]=true;
        for (i=1;i<=2*n;i++) {
            for (j=0;j<=n;j++) {
                if (a[i]>=a[i-1]) {
                    f[i][j][0]|=f[i-1][j][0];
                }
                if (a[i]>=b[i-1]) {
                    f[i][j][0]|=f[i-1][j][1];
                }
                if (b[i]>=a[i-1]) {
                    f[i][j][1]|=f[i-1][j-1][0];
                }
                if (b[i]>=b[i-1]) {
                    f[i][j][1]|=f[i-1][j-1][1];
                }
            }
        }
        if (f[2*n][n][0]) {
            Trace(2*n,n,0);
        }
        else if (f[2*n][n][1]) {
            Trace(2*n,n,1);
        }
        else {
            cout<<-1;
        }
    }
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 89