Submission #470797

#	Time	Username	Problem	Language	Result	Execution time	Memory
470797		Ya_Ali	Xylophone (JOI18_xylophone)	C++17	100 / 100	137 ms	496 KiB

xylophone

/* ** *** In the name of God *** ** */
// Only Haider is Amir al-Momenin
#include <bits/stdc++.h>
#include "xylophone.h"
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
const ll maxn = 5e3 + 5;
const ll mod = 1e9 + 7;
#define endl '\n'
#define all(x) x.begin(), x.end()
#define kill(x) return cout << x, 0
#define m (lx + rx) / 2
#define L 2 * x + 1
#define R L + 1
ll b1[maxn], b2[maxn], d1[maxn], d2[maxn];
bool flag1[maxn], flag2[maxn];
void build_b1(int n){
	flag1[1] = 1;
        for(ll i = 1; i < n; i ++){     
                if(flag1[i])b1[i + 1] = b1[i] + d1[i];
                else b1[i + 1] = b1[i] - d1[i];
                if(i < n - 1){
                        if(d2[i] == d1[i] + d1[i + 1])flag1[i + 1] = flag1[i];
                        else flag1[i + 1] = !flag1[i];
                }
        }
	ll mn = (n * 10);
	for(ll i = 1; i <= n; i++) mn = min(mn, b1[i]);
	for(ll i = 1; i <= n; i++) b1[i] += (1 - mn);
}
void build_b2(int n){
        flag2[1] = 0;
        for(ll i = 1; i < n; i ++){
                if(flag2[i])b2[i + 1] = b2[i] + d1[i];
                else b2[i + 1] = b2[i] - d1[i];
                if(i < n - 1){
                        if(d2[i] == d1[i] + d1[i + 1])flag2[i + 1] = flag2[i];
                        else flag2[i + 1] = !flag2[i];
                }
        }
        ll mn = (n * 10);
        for(ll i = 1; i <= n; i++) mn = min(mn, b2[i]);
        for(ll i = 1; i <= n; i++) b2[i] += (1 - mn);
}
void solve(int n){
	for(ll i = 1; i < n; i ++)d1[i] = query(i, i + 1);
	for(ll i = 1; i < n - 1; i ++)d2[i] = query(i, i + 2);
	build_b1(n); build_b2(n);
	ll p1, pn;
	for(ll i = 1; i <= n; i ++){
		if(b1[i] == 1)p1 = i;
		if(b1[i] == n)pn = i;
	}
	if(p1 > pn)
		for(ll i = 1; i <= n; i ++)answer(i, b2[i]);
	else
		for(ll i = 1; i <= n; i ++)answer(i, b1[i]);
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:55:2: warning: 'pn' may be used uninitialized in this function [-Wmaybe-uninitialized]
   55 |  if(p1 > pn)
      |  ^~
xylophone.cpp:55:2: warning: 'p1' may be used uninitialized in this function [-Wmaybe-uninitialized]

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