Submission #484005

#	Time	Username	Problem	Language	Result	Execution time	Memory
484005		MilosMilutinovic	Xylophone (JOI18_xylophone)	C++14	100 / 100	362 ms	640 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}());
const ll mod=1000000007;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head

const int N=5010;
int n,a[N],x[N],y[N];
VI ans;
//int query(int l,int r) {
//	int mn=(1<<29),mx=0;
//	rep(i,l,r+1) mn=min(mn,a[i]),mx=max(mx,a[i]);
//	return mx-mn;
//}
int check(int r) {
	rep(i,1,n+1) {
		VI v={i};
		rep(j,1,n) {
			v.pb(v.back()+x[j]*r);
			if (j!=n-1) if (y[j]!=x[j]+x[j+1]) r=(r==-1?1:-1);
		}
		int px,py;
		rep(j,0,n) if (v[j]==1) px=j;
		rep(j,0,n) if (v[j]==n) py=j;
		if (*min_element(all(v))==1&&*max_element(all(v))==n) {
			vector<bool> was(n+1,false);
			rep(j,0,n) was[v[j]]=true;
			bool ok=true;
			rep(j,1,n+1) if (!was[j]) ok=false;
			if (ok&&px<py) {
				ans=v;
				return i;
			}
		}
	}
	return -1;
}
void solve(int N) {
	n=N;
	rep(i,1,n) x[i]=query(i,i+1);
	rep(i,1,n-1) y[i]=query(i,i+2);
	check(-1);
	check(1);
	assert(SZ(ans)>0);
//	rep(i,0,n) printf("%d ",ans[i]);
	rep(i,0,n) answer(i+1,ans[i]);
}
//int main() {
//	scanf("%d",&n);
//	rep(i,1,n+1) scanf("%d",a+i);
//	solve(n);
//}
/*
5
2 1 5 3 4
*/

Compilation message (stderr)

xylophone.cpp: In function 'int check(int)':
xylophone.cpp:46:14: warning: 'py' may be used uninitialized in this function [-Wmaybe-uninitialized]
   46 |    if (ok&&px<py) {
      |            ~~^~~
xylophone.cpp:46:14: warning: 'px' may be used uninitialized in this function [-Wmaybe-uninitialized]

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