Submission #936371

#	Time	Username	Problem	Language	Result	Execution time	Memory
936371		velislavgarkov	Candies (JOI18_candies)	C++14	100 / 100	106 ms	15932 KiB

candies

#include <iostream>
#include <queue>
using namespace std;
#define endl '\n'
const int MAXN=2e5+10;
struct Node {
    long long pl;
    int l, r;
    int idx;
    bool friend operator < (Node a, Node b) {
        return a.pl<b.pl;
    }
};
priority_queue <Node> q;
int lef[MAXN], ri[MAXN], ind[MAXN], cnt;
long long a[MAXN], pref[MAXN];
bool used[2*MAXN];
long long find_sum(int l, int r) {
    if (l==1) return pref[r];
    return pref[r]-pref[l-2];
}
int main () {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    for (int i=1;i<=n;i++) {
        cin >> a[i];
        if (i==1) pref[i]=a[i];
        else pref[i]=pref[i-2]+a[i];
        lef[i]=ri[i]=i;
        q.push({a[i],i,i,i});
        ind[i]=i;
    }
    long long sum=0;
    cnt=n+2;
    for (int i=1;i<=n/2+n%2;i++) {
        while (used[q.top().idx]) q.pop();
        auto p=q.top();
        q.pop();
        sum+=p.pl;
        cout << sum << endl;
        used[p.idx]=true;
        if (p.l==1) {
            used[ind[ri[p.r+1]]]=used[ind[p.r+1]]=true;
            lef[ri[p.r+1]]=0;
            continue;
        }
        if (p.r==n) {
            used[ind[lef[p.l-1]]]=used[ind[p.l-1]]=true;
            ri[lef[p.l-1]]=n+1;
            continue;
        }
        int newl, newr;
        newl=lef[p.l-1];
        newr=ri[p.r+1];
        ri[newl]=newr;
        lef[newr]=newl;
        used[ind[newl]]=used[ind[newr]]=true;
        used[ind[p.l-1]]=used[ind[p.r+1]]=true;
        if (newl==0 || newr==n+1) continue;
        cnt++;
        ind[newl]=ind[newr]=cnt;
        long long ch=find_sum(newl,newr)-find_sum(newl+1,newr-1);
        q.push({ch,newl,newr,cnt});
    }
    return 0;
}
/*
10
3 10 5 1 8 6 4 7 2 9
*/

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