Submission #402436

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Source Code Expand

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;

class Myon
{
    public Myon() { }
    public static int Main()
    {
        new Myon().calc();
        return 0;
    }

    Scanner cin;

    void calc()
    {
        cin = new Scanner();
        int N = cin.nextInt();
        int[] H = new int[N];
        int[] S = new int[N];
        for (int i = 0; i < N; i++)
        {
            H[i] = cin.nextInt();
            S[i] = cin.nextInt();
        }

        long left = 0; //達成不可能な最大数
        long right = (long)1e18; //達成可能な最小数
        while (right - left > 1)
        {
            long mid = (left + right) / 2;
            if (check(H, S, mid)) right = mid;
            else left = mid;
        }
        Console.WriteLine(right);
    }

    bool check(int[] H, int[] S, long mid)
    {
        int N = H.Length;
        int[] bucket = new int[N + 1];
        for (int i = 0; i < N; i++)
        {
            if (H[i] > mid) return false;
            int sec = (int)Math.Min(N, (mid - H[i]) / S[i]);
            bucket[sec]++;
        }

        int[] array = new int[N];
        int cnt = 0;
        for (int i = 0; i <= N; i++)
        {
            for (int j = 0; j < bucket[i]; j++)
            {
                array[cnt++] = i;
            }
        }

        for (int i = 0; i < N; i++)
        {
            if (array[i] < i) return false;
        }
        return true;
    }
}





class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        i = 0;
        return s[i++];
    }

    public int nextInt()
    {
        return int.Parse(next());
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }

}

Submission Info

Judge Result