Submission #996159

#	Time	Username	Problem	Language	Result	Execution time	Memory
996159		vjudge1	Xylophone (JOI18_xylophone)	C++17	100 / 100	368 ms	97664 KiB

xylophone

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

int a[5005],d[5005][5005];

void solve(int n){
	int _=query(1,2);
	for(int i=3; i<=n; i++) d[i-2][i]=query(i-2,i);
	for(int i=2; i<=n; i++) d[i-1][i]=query(i-1,i);
	for(int i=1; i<=n; i++){
		a[1]=i;
		for(int __=-1; __<=1; __+=2){
			vector <int> vis(n+1,0);
			vis[a[1]]++;
			a[2]=a[1]+__*_;
			if(a[2]>=1 and a[2]<=n) vis[a[2]]++;
			int cnt=0;
			for(int j=3; j<=n; j++){
				int v=d[j-2][j];
				int l=d[j-1][j];
				if(v==max(a[j-1],a[j-2])-min(a[j-1],a[j-2])){
					if(a[j-1]>a[j-2]) a[j]=a[j-1]-l;
					else a[j]=a[j-1]+l;
				}else{
					int ifmin=a[j-1]-l;
					int ifmax=a[j-1]+l;
					if(ifmin>0 and max({a[j-2],a[j-1]})-ifmin==v) a[j]=ifmin;
					else a[j]=ifmax;
				}
				if(a[j]>=1 and a[j]<=n) vis[a[j]]++;
			}
			int fir=1,last=0;
			for(int j=1; j<=n; j++) if(a[j]==1) fir=j;
			for(int j=1; j<=n; j++) if(a[j]==n) last=j;
			if(fir>last) continue;
			bool ck=1;
			for(int i=1; i<=n; i++) if(vis[i]!=1) ck=0;
			if(!ck) continue;
			for(int i=1; i<=n; i++) answer(i,a[i]);
			return;
		}
	}
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:18:8: warning: unused variable 'cnt' [-Wunused-variable]
   18 |    int cnt=0;
      |        ^~~

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