Codeforces Round 623(Div. 2,based on VK Cup 2019-2020 - Elimination Round,Engine)D. Recommendations

VK news recommendation system daily selects interesting publications of one of n disjoint categories for each user. Each publication belongs to exactly one category. For each category i batch algorithm selects ai publications.

The latest A/B test suggests that users are reading recommended publications more actively if each category has a different number of publications within daily recommendations. The targeted algorithm can find a single interesting publication of i-th category within ti seconds.

What is the minimum total time necessary to add publications to the result of batch algorithm execution, so all categories have a different number of publications? You can’t remove publications recommended by the batch algorithm.

Input

The first line of input consists of single integer n — the number of news categories (1≤n≤200000).

The second line of input consists of n integers ai — the number of publications of i-th category selected by the batch algorithm (1≤ai≤109).

The third line of input consists of n integers ti — time it takes for targeted algorithm to find one new publication of category i (1≤ti≤105).

Output

Print one integer — the minimal required time for the targeted algorithm to get rid of categories with the same size.

Examples

inputCopy

5

3 7 9 7 8

5 2 5 7 5

outputCopy

6

inputCopy

5

1 2 3 4 5

1 1 1 1 1

outputCopy

0

Note

In the first example, it is possible to find three publications of the second type, which will take 6 seconds.

In the second example, all news categories contain a different number of publications.

优先队列，每次都让某一位上的全职最小的加1，2，3然后处理。

#include <bits/stdc++.h>

using namespace std;

int n, t, a[3000000];

struct node

{

    int first, second;

    bool operator<(const node &b) const

    {

        if (first == b.first)

            return second < b.second;

        else

            return first > b.first;

    }

};

priority_queue<node> ms;

int main()

{

    cin >> n;

    for (int i = 0; i < n; ++i)

    {

        cin >> a[i];

    }

    for (int i = 0; i < n; ++i)

    {

        int b;

        cin >> b;

        ms.push(node{a[i], b});

    }

    long long cnt = 0;

    while (ms.size())

    {

        auto po = ms.top();

        ms.pop();

       //cout << po.first << " " << po.second << endl;

        //cout << 1 << endl;

        if (ms.empty())

            break;

            int f=1;

        while (po.first == ms.top().first && ms.size())

        {

            auto pi = ms.top();

            //cout<<pi.first + 1<<" "<<pi.second<<endl;

            ms.pop();

            ms.push(node{pi.first + f, pi.second});

            cnt += pi.second;

            f++;

          //  cout << cnt << endl;

            // cout<<ms.top().first<<endl;

            // cout << ms.size() << endl;

        }

    }

    cout << cnt << endl;

}

上分代码的思路确实有问题，时间复杂度太高。思路差不多，都是先处理权值大的，让权值小移动。

#include <bits/stdc++.h>

using namespace std;

int n, t;

struct node

{

    int data;

    long long  cost;

    bool operator<(const node &b) const

    {

        if (cost == b.cost)

            return data < b.data;

        else

            return cost > b.cost;

    }

} a[3000000];

map<int, int> fa;

int find(int a)

{

    if (fa[a] == 0)

        return a;

    else

        return fa[a] = find(fa[a]);

}

void unite(int x, int y)

{

    x = find(x);

    y = find(y);

    if (x != y)

        fa[x] = y;

}

int main()

{

    cin >> n;

    fa.clear();

    for (int i = 0; i < n; ++i)

        scanf("%d", &a[i].data);

    for (int i = 0; i < n; ++i)

        scanf("%lld", &a[i].cost);

    sort(a, a + n);

    long long ans = 0;

    for (int i = 0; i < n; i++)

    {

        int x=find(a[i].data) ;

        ans += a[i].cost * (x- a[i].data);

        unite(x,x+1);

    }

    cout << ans << endl;

}

巴特西

Codeforces Round 623(Div. 2,based on VK Cup 2019-2020 - Elimination Round,Engine)D. Recommendations

最新文章

热门文章