Submission #413145

#	Time	Username	Problem	Language	Result	Execution time	Memory
413145		NintsiChkhaidze	Building 4 (JOI20_building4)	C++14	0 / 100	3 ms	460 KiB

building4

#include <bits/stdc++.h>
#define pb push_back
#define ll  long long
#define s second
#define f first
using namespace std;
const int N = 500005;
int a[N],b[N],c[N],A,B;
char s[N];
int main (){
    ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
    int n;
    cin>>n;
    n*=2;
    for (int i=1;i<=n;i++)  cin>>a[i];
    for (int i=1;i<=n;i++)  cin>>b[i];
    int last = 0;
    bool check=1;
    for (int i=1;i<=n;i++){
        if (a[i] >= last && b[i] >= last){
            if (a[i] < b[i]) A++,c[i] = a[i],s[i] = 'A';
            else B++,c[i] = b[i],s[i] = 'B';
        }
        else if (a[i] >= last) A++,c[i] = a[i],s[i] = 'A';
        else if (b[i] >= last) B++,c[i] = b[i],s[i] = 'B';
        else {check=0; break;}
        last = c[i];
    }
    c[n+1]=1e9;
    for (int i=n;i>=1;i--){
        if (A > B && s[i] == 'B') continue;
        if (B > A && s[i] == 'A') continue;
        if (A == B) continue;
        if (s[i] == 'B') {
            if (a[i] >= c[i - 1] && a[i] <= c[i+1]) 
                B--,A++,c[i] = a[i],s[i] = 'A';
        }
        else {
            if (b[i] >= c[i - 1] && b[i] <= c[i+1]) 
                A--,B++,c[i] = b[i],s[i] = 'B';
        }
    }
    if (!check || A!=B) cout<<-1;
    else{
        for (int i=1;i<=n;i++)
            cout<<s[i];
    }
}

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