Submission #1070529

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070529		_8_8_	Xylophone (JOI18_xylophone)	C++17	100 / 100	76 ms	98648 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;
int p[5002],a[5002],mem[5002][5002];
int QQ(int l,int r) {
	if(mem[l][r] != -1) {
		return mem[l][r];
	}
	return mem[l][r] = query(l,r);
}
int n_;
bool bad(int x) {
	return (x < 1 || x > n_ || p[x]);
}
void make(int v,int val) {
	a[v] = val;
	p[val] = v;
}
void solve(int n) {
	n_ = n;
	memset(mem,-1,sizeof(mem));
	memset(p,0,sizeof(p));
	memset(a,0,sizeof(a));
	int nd = n - 1;
	int l = 1,r = n;
	while(r - l > 1) {
		int mid = (l + r) >> 1;
		if(QQ(1,mid) == nd) {
			r = mid;
		} else {
			l = mid;
		}
	}
	p[n] = r;
	l = 1,r = p[n];
	while(r - l > 1) {
		int mid = (l + r) >> 1;
		if(QQ(mid,p[n]) == nd) {
			l = mid;
		} else {
			r = mid;
		}
	}
	p[1] = l;
	a[p[1]] = 1;
	a[p[n]] = n;
	int mx = 1;
	if(p[1] - 1 >= 1) {
		make(p[1] - 1,1 + QQ(p[1] - 1,p[1]));
	}
	for(int i = p[1] - 2;i >= 1;i--) {
		int t2, t1, val;
		int t = QQ(i,i + 1);
		if(bad(a[i + 1] + t))  {
			val = a[i + 1] - t;
		} else if(bad(a[i + 1] - t)) {
			val = a[i + 1] + t;
		}
		else {
			t2 = QQ(i,i + 2);
			if(a[i + 2] > a[i + 1]) {
				if(t2 == a[i + 2] - (a[i + 1] - t)) {
					val = a[i + 1] - t;
				} else {
					val = a[i + 1] + t;
				}
			} else {
				if(t2 == a[i + 1] + t - a[i + 2]) {
					val = a[i + 1] + t;
				} else {
					val = a[i + 1] - t;
				}
			}
		}
		p[val] = i;
		a[i] = val;
	}
	mx = 1;
	if(p[1] + 1 < p[n]) {
		make(p[1] + 1,1 + QQ(p[1],p[1]+1));
	}
	for(int i = p[1] + 2;i < p[n];i++) {
		int val;
		int t2, t1;
		int t = QQ(i - 1,i);
		if(bad(a[i - 1] + t))  {
			val = a[i - 1] - t;
		} else if(bad(a[i - 1] - t)) {
			val = a[i - 1] + t;
		} else{
			t2 = QQ(i - 2,i);
			if(a[i - 2] > a[i - 1]) {
				if(t2 == a[i - 2] - (a[i - 1] - t)) {
					val = a[i - 1] - t;
				} else {
					val = a[i - 1] + t;
				}
			} else {
				if(t2 == a[i - 1] + t - a[i - 2]) {
					val = a[i - 1] + t;
				} else {
					val = a[i - 1] - t;
				}
			}
		}
		// cout << i << ' ' << val << '\n';
		p[val] = i;
		a[i] = val;
	}
	int mn = n;
	if(p[n] + 1 <= n) {
		make(p[n] + 1,n - QQ(p[n],p[n]+1));
	}
	for(int i = p[n] + 2;i <= n;i++) {
		int val;
		int t2, t1;
		int t = QQ(i - 1,i);
		if(bad(a[i - 1] + t))  {
			val = a[i - 1] - t;
		} else if(bad(a[i - 1] - t)) {
			val = a[i - 1] + t;
		} else{
			t2 = QQ(i - 2,i);
			if(a[i - 2] > a[i - 1]) {
				if(t2 == a[i - 2] - (a[i - 1] - t)) {
					val = a[i - 1] - t;
				} else {
					val = a[i - 1] + t;
				}
			} else {
				if(t2 == a[i - 1] + t - a[i - 2]) {
					val = a[i - 1] + t;
				} else {
					val = a[i - 1] - t;
				}
			}
		}
		p[val] = i;
		a[i] = val;
	}
	for(int i = 1;i <= n;i++) {
		answer(p[i],i);
	}
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:52:11: warning: unused variable 't1' [-Wunused-variable]
   52 |   int t2, t1, val;
      |           ^~
xylophone.cpp:84:11: warning: unused variable 't1' [-Wunused-variable]
   84 |   int t2, t1;
      |           ^~
xylophone.cpp:116:11: warning: unused variable 't1' [-Wunused-variable]
  116 |   int t2, t1;
      |           ^~
xylophone.cpp:47:6: warning: variable 'mx' set but not used [-Wunused-but-set-variable]
   47 |  int mx = 1;
      |      ^~
xylophone.cpp:110:6: warning: unused variable 'mn' [-Wunused-variable]
  110 |  int mn = n;
      |      ^~

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