Submission #786980

#	Time	Username	Problem	Language	Result	Execution time	Memory
786980		winter0101	Xylophone (JOI18_xylophone)	C++14	100 / 100	56 ms	472 KiB

xylophone

#include<bits/stdc++.h>
#include <xylophone.h>
#define fastio ios_base::sync_with_stdio(false);cin.tie(nullptr);
using namespace std;
int a[10009];
int pos[10009];
void solve(int n){
for (int i=1;i<=2*n;i++){
    pos[i]=0;
}
int l=1,r=n;
int pos1=1;
while (l<=r){
    int mid=(l+r)/2;
    int dd=query(mid,n);
    if (dd==n-1){
        l=mid+1;
        pos1=mid;
    }
    else {
        r=mid-1;
    }
}
a[pos1]=1;
pos[1]=1;
answer(pos1,1);
if (pos1<n){
a[pos1+1]=query(pos1,pos1+1)+1;
pos[a[pos1+1]]=1;
answer(pos1+1,a[pos1+1]);
for (int i=pos1+2;i<=n;i++){
    int d=query(i-1,i);
     if (a[i-1]+d>n||pos[a[i-1]+d]){
        a[i]=a[i-1]-d;
        pos[a[i]]=1;
        answer(i,a[i]);
     	continue;
     }
     if (a[i-1]-d<=0||pos[a[i-1]-d]){
     	a[i]=a[i-1]+d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     	continue;
     }
     int r=query(i-2,i);
     if (a[i-2]<a[i-1]){
     	if (a[i-1]+d==a[i-2]+r)a[i]=a[i-1]+d;
     	else a[i]=a[i-1]-d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     }
     else {
     	if (a[i-1]-d==a[i-2]-r)a[i]=a[i-1]-d;
     	else a[i]=a[i-1]+d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     }
}
}
if (pos1>1){
a[pos1-1]=query(pos1-1,pos1)+1;
pos[a[pos1-1]]=1;
answer(pos1-1,a[pos1-1]);
for (int i=pos1-2;i>=1;i--){
     int d=query(i,i+1);
     if (a[i+1]+d>n||pos[a[i+1]+d]){
        a[i]=a[i+1]-d;
        pos[a[i]]=1;
        answer(i,a[i]);
     	continue;
     }
     if (a[i+1]-d<=0||pos[a[i+1]-d]){
     	a[i]=a[i+1]+d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     	continue;
     }
     int r=query(i,i+2);
     if (a[i+2]<a[i+1]){
     	if (a[i+1]+d==a[i+2]+r)a[i]=a[i+1]+d;
     	else a[i]=a[i+1]-d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     }
     else {
     	if (a[i+1]-d==a[i+2]-r)a[i]=a[i+1]-d;
     	else a[i]=a[i+1]+d;
     	pos[a[i]]=1;
     	answer(i,a[i]);
     }
}
}   
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 53 / 53