Submission #996088

#	Time	Username	Problem	Language	Result	Execution time	Memory
996088		BuzzyBeez	Xylophone (JOI18_xylophone)	C++17	100 / 100	135 ms	1104 KiB

xylophone

#include<bits/stdc++.h>
#include "xylophone.h"
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<int>
#define vii vector<vi>
#define pint pair<int,int>
#define vpint vector<pint>
#define aint(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 1e9+7;
const ll inf = 1e18;
const ll base = 31;
const ll blocksz = 320;
const ll N = 1e4+8;
const ll buff = 1e5+1;
int a[N],dist[N][2];
int pos[5008];

bool check(int n) {
	fill(pos + 1, pos + n + 1, 0);
	for (int i = 1; i <= n; ++i)
		if (a[i] <= 0 || a[i] > n) return 0;
		else pos[a[i]] = i;
	for (int i = 1; i <= n; ++i) if (!pos[i]) return 0;
	return pos[1] < pos[n];
}

void solve(int n){
    for(int i = 2; i <= n; i++){
        if(i > 1) dist[i][0] = query(i-1,i);
        if(i > 2) dist[i][1] = query(i-2,i);
    }
    for(int x = 1; x <= n; x++){
        a[1] = x;
        a[2] = x+dist[2][0];
        for(int i = 3; i <= n; i++){
           	if(a[i-2] > a[i-1]){
                if (a[i-2]-a[i-1]+dist[i][0] == dist[i][1]) a[i] = a[i-1]-dist[i][0];
                else a[i] = a[i-1]+dist[i][0];
            }
            else{
                if (a[i-1]-a[i-2]+dist[i][0] == dist[i][1]) a[i] = a[i-1]+dist[i][0];
                else a[i] = a[i-1]-dist[i][0];
            }
        }
        if(check(n)) break;
        a[1] = x;
        a[2] = x-dist[2][0];
        for(int i = 3; i <= n; i++){
            if(a[i-2] > a[i-1]){
                if (a[i-2]-a[i-1]+dist[i][0] == dist[i][1]) a[i] = a[i-1]-dist[i][0];
                else a[i] = a[i-1]+dist[i][0];
            }
            else{
                if (a[i-1]-a[i-2]+dist[i][0] == dist[i][1]) a[i] = a[i-1]+dist[i][0];
                else a[i] = a[i-1]-dist[i][0];
            }
        }
        if(check(n)) break;
    }
    for(int i = 1; i <= n; i++) answer(i,a[i]);
}

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