Submission #1257112

#	Time	Username	Problem	Language	Result	Execution time	Memory
1257112		Thunnus	Xylophone (JOI18_xylophone)	C++20	0 / 100	0 ms	408 KiB

xylophone

#include<bits/stdc++.h>
#include "xylophone.h"
using namespace std;
using i64 = long long;
//#define int i64
#define vi vector<int>
#define vvi vector<vi>
#define vb vector<bool>
#define pii pair<int, int>
#define fi first
#define se second
#define sz(x) (int)(x).size()

// index[1] < index[n] 

void solve(int n){
    vi diff(n + 1);
    for(int i = 2; i <= n; i++){
        diff[i] = query(i - 1, i);
        if(i - 2 >= 1){
            int tri = query(i - 2, i);
            if(tri != diff[i] + diff[i - 1]){
                diff[i] = -diff[i]; // change direction, increasing->decreasing or decreasing->increasing
            }
        }
    }

    vi pref(n + 1);
    int mn = -1, mx = -1;
    for(int i = 2; i <= n; i++){
        pref[i] = diff[i] + pref[i - 1];
        if(mx == -1 || pref[i] > pref[mx]){
            mx = i;
        }
        else if(mn == -1 || pref[i] < pref[mn]){
            mn = i;
        }
    }
    if(mn > mx){ // index[1] (mn) < index[n] (mx)
        for(int i = 2; i <= n; i++){
            diff[i] = -diff[i];
        }
        swap(mn, mx);
    }

    vi ans(n + 1);
    ans[mx] = n, ans[mn] = 1;
    for(int i = mx - 1; i >= 1; i--){
        ans[i] = ans[i + 1] - diff[i + 1];
    }
    for(int i = mx + 1; i <= n; i++){
        ans[i] = ans[i - 1] + diff[i];
    }
    for(int i = 1; i <= n; i++){
        answer(i, ans[i]);
    }
    return;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 36
• Subtask 3: 0 / 53