Submission #773190

#	Time	Username	Problem	Language	Result	Execution time	Memory
773190		GrindMachine	Candies (JOI18_candies)	C++17	100 / 100	481 ms	30348 KiB

candies

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi of apio 2007 backup

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    ll n; cin >> n;
    vector<ll> a(n+5);
    rep1(i,n) cin >> a[i];

    set<array<ll,3>> segs;
    set<array<ll,3>> costs;
    rep1(i,n){
        segs.insert({i,i+1,a[i]});
        costs.insert({a[i],i,i+1});
    }

    ll ans = 0;

    rep1(iter,ceil2(n,2)){
        auto [mx,l,r] = *costs.rbegin();
        ans += mx;
        cout << ans << endl;

        auto it = segs.lower_bound({l,r,mx});

        array<ll,3> ar1, ar2;
        ar1.fill(-1);
        ar2.fill(-1);

        if(it != segs.begin()){
            ar1 = *prev(it); 
        }
        if(next(it) != segs.end()){
            ar2 = *next(it);
        }

        if(ar1[0] != -1){
            segs.erase(ar1);
            costs.erase({ar1[2], ar1[0], ar1[1]});
        }

        if(ar2[0] != -1){
            segs.erase(ar2);
            costs.erase({ar2[2], ar2[0], ar2[1]});
        }

        if(ar1[0] != -1 and ar2[0] != -1){
            ll l = ar1[0], r = ar2[1], cost = ar1[2]+ar2[2]-mx;
            segs.insert({l,r,cost});
            costs.insert({cost,l,r});
        }

        segs.erase({l,r,mx});
        costs.erase({mx,l,r});
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 92 / 92