Submission #654396

#	Time	Username	Problem	Language	Result	Execution time	Memory
654396		uylulu	Xylophone (JOI18_xylophone)	C++14	47 / 100	89 ms	416 KiB

xylophone

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

const int N = 5e3 + 5;

int res[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;
	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;
		}
		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;
				}
			}
		}
	}
	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;
		}
		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;
				}
			}
		}
	}
	for(int i = 1;i <= n;i++) {
		answer(i,res[i]);
	}
	return;
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:10:18: warning: unused variable 'tr' [-Wunused-variable]
   10 |  int l = 1,r = n,tr;
      |                  ^~
xylophone.cpp:11:6: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   11 |  int pos;
      |      ^~~

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