Submission #1207986

#	Time	Username	Problem	Language	Result	Execution time	Memory
1207986		garam1732	Shortcut (IOI16_shortcut)	C++20	97 / 100	2089 ms	78592 KiB

shortcut

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

#define ff first
#define ss second
#define bl ' '
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define comp(v) (v).erase(unique(all(v)), (v).end())
#define lbd(v,x) lower_bound(all(v), (x))-(v).begin()
#define ubd(v,x) upper_bound(all(v), (x))-(v).begin()

typedef long long ll;
typedef pair<int, int> pi;
typedef pair<pi, int> pii;
typedef pair<int, pi> ipi;
typedef pair<pi, pi> pipi;
typedef pair<ll, ll> pll;

const int MAXN = 100100*10;
const ll MOD = 998244353;
const ll INF = 1e16;

ll sum[MAXN], w[MAXN];
int N, C;

vector<pll> v;
int sz;

pll mx1 = {-INF, 0}, mx2 = {-INF, 0};
pll mn1[MAXN], mn2[MAXN];

bool solve(ll L) {
    ll mnsum, mxsum, mndif, mxdif;
    mnsum = mndif = -INF, mxsum = mxdif = INF;

    for(int i=N-1; i>=0; i--) {
        int it = lbd(v, pll(L+sum[i]-w[i]+1, 0));
        ll mn = (mn1[it].ss == i ? mn2[it].ff : mn1[it].ff);
        ll mx = (mx1.ss == i ? mx2.ff : mx1.ff);
        if(mn != INF && mx > L+sum[i]-w[i]) {
            mn += L-w[i]-C; mx += -L+w[i]+C;
            mnsum = max(mnsum, sum[i]+mx); mxsum = min(mxsum, sum[i]+mn);
            mndif = max(mndif, mx-sum[i]); mxdif = min(mxdif, mn-sum[i]);
        }
    }//cout<<mnsum<<bl<<mxsum<<endl;

    for(int i=0; i<N-1; i++) {
        ll mn = max(mnsum-sum[i], mndif+sum[i]);
        ll mx = min(mxsum-sum[i], mxdif+sum[i]);
        
        int it = lower_bound(sum+i+1, sum+N, mn)-sum;
        if(it < N && sum[it] <= mx) return true;
    } return false;
}

long long find_shortcut(int n, std::vector<int> l, std::vector<int> d, int c)
{
    for(int i=1; i<n; i++) sum[i] = sum[i-1]+l[i-1];
    for(int i=0; i<n; i++) w[i]=d[i];
    N = n, C = c;

    for(int i=0; i<n; i++) v.push_back(pll(w[i]+sum[i], i));
    sort(all(v));

    for(int i=0; i<N; i++) {
        if(mx2.ff < sum[i]+w[i]) mx2 = pll(sum[i]+w[i], i);
        if(mx1 < mx2) swap(mx1, mx2);
    }

    mn1[N] = mn2[N] = pll(INF, 0);
    for(int i=N-1; i>=0; i--) {
        mn1[i] = mn1[i+1]; mn2[i] = mn2[i+1];
        
        int x = v[i].ss;
        if(mn2[i].ff > sum[x]-w[x]) mn2[i] = pll(sum[x]-w[x], x);
        if(mn1[i] > mn2[i]) swap(mn1[i], mn2[i]);
    }

    //for(int i=0; i<N; i++) cout<<mn1[i].ff<<bl;cout<<endl;

    //solve(80); return 0;

    ll lb = 0, ub = 1e16, mid;
    while(lb < ub) {
        mid = lb+ub>>1;

        if(solve(mid)) ub = mid;
        else lb = mid+1;
    }

	return lb;
}

Compilation message (stderr)

shortcut.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
shortcut_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 33 / 33
• Subtask 6: 22 / 22
• Subtask 7: 4 / 4
• Subtask 8: 0 / 3