Submission #1278360

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278360		sasde	Building 4 (JOI20_building4)	C++20	11 / 100	2098 ms	39840 KiB

building4

#include<bits/stdc++.h>
using namespace std;
bool M1;
#define PI 3.14159265358979323846
#define sz(a) (int)a.size()
#define all(x) x.begin(),x.end()
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<'\n'
#define look_time   cerr << "TIME : " << clock() * 0.001 << "s" <<'\n'
const int N=1e6+5,lg=30,mod=1e9+7,inf=1e9;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
 return u+rd()%(v-u+1);
}
int dx[]={1,0,-1,0,1,1,-1,-1};
int dy[]={0,-1,0,1,1,-1,1,-1};
int node,a[2][N];
ii dp[N][2];
bool M2;
void solve(){
    cin >> node ;
    for(int j=0;j<=1;++j)
    for(int i=1;i<=node*2;++i)cin >> a[j][i];
    for(int i=1;i<=node*2;++i){
        for(int j=0;j<=1;++j){
            dp[i][j]={inf,-inf};
            for(int k=0;k<=1;++k){
                if(a[j][i]<a[k][i-1])continue;
                dp[i][j].fi=min(dp[i][j].fi,dp[i-1][k].fi+(1-j));
                dp[i][j].se=max(dp[i][j].se,dp[i-1][k].se+(1-j));
            }
        }
    }
    int ok=-1;
    vector<int>res;
    for(int i=1;i<=node*2;++i)cerr <<dp[i][0].fi<<" "<<dp[i][0].se<<" "<<dp[i][1].fi<<" "<<dp[i][1].se<<'\n';
    for(int i=0;i<=1;++i){
        if(dp[node*2][i].fi<=node&&node<=dp[node*2][i].se){
            ok=i;
        }
    }
    // cout <<ok<<" "<<node<<'\n';
    if(ok==-1){
        cout <<-1;return;
    }
    int cnt=node;
    for(int i=node*2;i>=1;--i){
        res.emb(ok);
        cnt-=(1-ok);
        int val=a[ok][i];
        if(val>=a[0][i-1]&&dp[i-1][0].fi<=cnt&&cnt<=dp[i-1][0].se)ok=0;
        else ok=1;
    }
    reverse(all(res));
    for(auto x:res)cout <<(!x?'A':'B');
}
main()
{
  srand(time(0));
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    #define task "aws"
    if(fopen(task".inp","r")){
      freopen(task".inp","r",stdin);
      freopen(task".out","w",stdout);
    }
    int t=1;
 //   cin >> t;
while(t--){
    solve();
}
look_memory;
look_time;
}

Compilation message (stderr)

building4.cpp:71:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   71 | main()
      | ^~~~
building4.cpp: In function 'int main()':
building4.cpp:79:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |       freopen(task".inp","r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
building4.cpp:80:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |       freopen(task".out","w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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