제출 #654402

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
654402		uylulu	Xylophone (JOI18_xylophone)	C++14	100 / 100	86 ms	428 KiB

xylophone

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

const int N = 5e3 + 5;

int res[N + 1];

bool check[N + 1];

void solve(int n) {
	int l = 1,r = n,tr;
	int pos;

	while(l < r) {
		int mid = (l + r)/2;
		if(query(mid,n) >= n - 1) {
			l = mid + 1;
			pos = mid;
		} else {
			r = mid;
		}
	} 

	res[pos] = 1;
	check[1] = true;
	for(int i = pos - 1;i >= 1;i--) {
		int w = query(i,i + 1);

		if(res[i + 1] + w > n) {
			res[i] = res[i + 1] - w;
			continue;
		}
		if(res[i + 1] <= w) {
			res[i] = res[i + 1] + w;
			continue;
		}
		if(check[res[i + 1] - w]) {
			res[i] = res[i + 1] + w;
			continue;
		} 
		if(check[res[i + 1] + w]) {
			res[i] = res[i + 1] - w;
			continue;
		}
		vector<int> st = {res[i + 1],res[i + 2]};
		sort(st.begin(),st.end());

		int asd = query(i,i + 2);
		if(asd == st[1] - st[0]) {
			if(res[i + 1] == st[0]) {
				res[i] = res[i + 1] + w;
			} else {
				res[i] = res[i + 1] - w;
			}
		} else {
			if(asd == w) {
				if(res[i + 1] == st[0]) {
					res[i] = res[i + 1] + w;
				} else {
					res[i] = res[i + 1] - w;
				}
			} else {
				if(res[i + 2] == st[0]) {
					res[i] = res[i + 2] + asd;
				} else {
					res[i] = res[i + 2] - asd;
				}
			}
		}
		check[res[i]] = true;
	}
	for(int i = pos + 1;i <= n;i++) {
		int w = query(i - 1,i);
		if(res[i - 1] <= w) {
			res[i] = res[i - 1] + w;
			continue;
		}
		if(res[i - 1] + w > n) {
			res[i] = res[i - 1] - w;
			continue;
		}
		if(check[res[i - 1] + w]) {
			res[i] = res[i - 1] - w;
			continue;
		}
		if(check[res[i - 1] - w]) {
			res[i] = res[i - 1] + w;
			continue;
		}
		vector<int> st = {res[i - 1],res[i - 2]};
		sort(st.begin(),st.end());

		int asd = query(i - 2,i);
		if(asd == st[1] - st[0]) {
			if(res[i - 1] == st[0]) {
				res[i] = res[i - 1] + w;
			} else {
				res[i] = res[i - 1] - w;
			}
		} else {
			if(asd == w) {
				if(res[i - 1] == st[0]) {
					res[i] = res[i - 1] + w;
				} else {
					res[i] = res[i - 1] - w;
				}
			} else {
				if(res[i - 2] == st[0]) {
					res[i] = res[i - 2] + asd;
				} else {
					res[i] = res[i - 2] - asd;
				}
			}
		}
		check[res[i]] = true;
	}
	for(int i = 1;i <= n;i++) {
		answer(i,res[i]);
	}
	return;
}

컴파일 시 표준 에러 (stderr) 메시지

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:12:18: warning: unused variable 'tr' [-Wunused-variable]
   12 |  int l = 1,r = n,tr;
      |                  ^~
xylophone.cpp:13:6: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   13 |  int pos;
      |      ^~~

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