Submission #3009491

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Source Code Expand

using System;

public class Hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var n = long.Parse(line[0]);
        var k = long.Parse(line[1]);
        var wd = new long[n, 2];
        var maxa = 0L;
        for (int i = 0; i < n; i++)
        {
            line = Console.ReadLine().Trim().Split(' ');
            wd[i, 0] = long.Parse(line[0]);
            wd[i, 1] = long.Parse(line[1]);
            maxa = Math.Max(maxa, wd[i, 0] + (k - 1) * wd[i, 1] + 100L);
        }
        Console.WriteLine(getAns(wd, k, maxa));
    }
    public static long getAns(long[,] wd, long k, long maxa)
    {
        var ok = maxa;
        var ng = 0L;
        while (ok - ng > 1)
        {
            var mid = (ok + ng) / 2L;
            if (getFLower(wd, mid, k)) ok = mid;
            else ng = mid;
        }
        return ok;
    }
    public static bool getFLower(long[,] wd, long a, long k)
    {
        var n = wd.GetLength(0);
        var f = 0L;
        for (int i = 0; i < n; i++)
            f += (a - wd[i, 0]) / wd[i, 1] + 1;
        return f >= k;
    }
}

Submission Info

Judge Result