using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; using System.Runtime.CompilerServices; using System.Runtime.InteropServices; using YukicoderContest255.Extensions; using YukicoderContest255.Questions; namespace YukicoderContest255.Questions { public class QuestionA : AtCoderQuestionBase { public override IEnumerable Solve(TextReader inputStream) { var (v, t, p) = inputStream.ReadValue(); var limit = v * (p + 1); const int startTime = 1; yield return SearchExtensions.BoundaryBinarySearch(time => { var susuru = (time - startTime - 1) / t; return time - startTime - susuru <= limit; }, 0, long.MaxValue); } } public static class SearchExtensions { class LowerBoundComparer : IComparer where T : IComparable { public int Compare(T x, T y) => 0 <= x.CompareTo(y) ? 1 : -1; } class UpperBoundComparer : IComparer where T : IComparable { public int Compare(T x, T y) => 0 < x.CompareTo(y) ? 1 : -1; } // https://trsing.hatenablog.com/entry/2019/08/27/211038 public static int GetGreaterEqualIndex(this ReadOnlySpan span, T inclusiveMin) where T : IComparable => ~span.BinarySearch(inclusiveMin, new UpperBoundComparer()); public static int GetGreaterThanIndex(this ReadOnlySpan span, T exclusiveMin) where T : IComparable => ~span.BinarySearch(exclusiveMin, new LowerBoundComparer()); public static int GetLessEqualIndex(this ReadOnlySpan span, T inclusiveMax) where T : IComparable => ~span.BinarySearch(inclusiveMax, new LowerBoundComparer()) - 1; public static int GetLessThanIndex(this ReadOnlySpan span, T exclusiveMax) where T : IComparable => ~span.BinarySearch(exclusiveMax, new UpperBoundComparer()) - 1; public static int GetGreaterEqualIndex(this Span span, T inclusiveMin) where T : IComparable => ((ReadOnlySpan)span).GetGreaterEqualIndex(inclusiveMin); public static int GetGreaterThanIndex(this Span span, T exclusiveMin) where T : IComparable => ((ReadOnlySpan)span).GetGreaterThanIndex(exclusiveMin); public static int GetLessEqualIndex(this Span span, T inclusiveMax) where T : IComparable => ((ReadOnlySpan)span).GetLessEqualIndex(inclusiveMax); public static int GetLessThanIndex(this Span span, T exclusiveMax) where T : IComparable => ((ReadOnlySpan)span).GetLessThanIndex(exclusiveMax); public static int BoundaryBinarySearch(Predicate predicate, int ok, int ng) { // めぐる式二分探索 while (Math.Abs(ok - ng) > 1) { int mid = (ok + ng) / 2; if (predicate(mid)) { ok = mid; } else { ng = mid; } } return ok; } public static long BoundaryBinarySearch(Predicate predicate, long ok, long ng) { while (Math.Abs(ok - ng) > 1) { long mid = (ok + ng) / 2; if (predicate(mid)) { ok = mid; } else { ng = mid; } } return ok; } public static double Bisection(Func f, double a, double b, double eps = 1e-9) { if (f(a) * f(b) >= 0) { throw new ArgumentException("f(a)とf(b)は異符号である必要があります。"); } const int maxLoop = 100; double mid = (a + b) / 2; for (int i = 0; i < maxLoop; i++) { if (f(a) * f(mid) < 0) { b = mid; } else { a = mid; } mid = (a + b) / 2; if (Math.Abs(b - a) < eps) { break; } } return mid; } } } namespace YukicoderContest255 { class Program { static void Main(string[] args) { IAtCoderQuestion question = new QuestionA(); var answers = question.Solve(Console.In); var writer = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false }; Console.SetOut(writer); foreach (var answer in answers) { Console.WriteLine(answer); } Console.Out.Flush(); } } } #region Base Class namespace YukicoderContest255.Questions { public interface IAtCoderQuestion { IEnumerable Solve(string input); IEnumerable Solve(TextReader inputStream); } public abstract class AtCoderQuestionBase : IAtCoderQuestion { public IEnumerable Solve(string input) { var stream = new MemoryStream(Encoding.Unicode.GetBytes(input)); var reader = new StreamReader(stream, Encoding.Unicode); return Solve(reader); } public abstract IEnumerable Solve(TextReader inputStream); } } #endregion #region Extensions namespace YukicoderContest255.Extensions { public static class TextReaderExtensions { public static int ReadInt(this TextReader reader) => int.Parse(ReadString(reader)); public static long ReadLong(this TextReader reader) => long.Parse(ReadString(reader)); public static double ReadDouble(this TextReader reader) => double.Parse(ReadString(reader)); public static string ReadString(this TextReader reader) => reader.ReadLine(); public static int[] ReadIntArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(int.Parse).ToArray(); public static long[] ReadLongArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(long.Parse).ToArray(); public static double[] ReadDoubleArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(double.Parse).ToArray(); public static string[] ReadStringArray(this TextReader reader, char separator = ' ') => reader.ReadLine().Split(separator); // Supports primitive type only. public static T1 ReadValue(this TextReader reader) => (T1)Convert.ChangeType(reader.ReadLine(), typeof(T1)); public static (T1, T2) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); return (v1, v2); } public static (T1, T2, T3) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); return (v1, v2, v3); } public static (T1, T2, T3, T4) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); var v4 = (T4)Convert.ChangeType(inputs[3], typeof(T4)); return (v1, v2, v3, v4); } public static (T1, T2, T3, T4, T5) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); var v4 = (T4)Convert.ChangeType(inputs[3], typeof(T4)); var v5 = (T5)Convert.ChangeType(inputs[4], typeof(T5)); return (v1, v2, v3, v4, v5); } public static (T1, T2, T3, T4, T5, T6) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); var v4 = (T4)Convert.ChangeType(inputs[3], typeof(T4)); var v5 = (T5)Convert.ChangeType(inputs[4], typeof(T5)); var v6 = (T6)Convert.ChangeType(inputs[5], typeof(T6)); return (v1, v2, v3, v4, v5, v6); } public static (T1, T2, T3, T4, T5, T6, T7) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); var v4 = (T4)Convert.ChangeType(inputs[3], typeof(T4)); var v5 = (T5)Convert.ChangeType(inputs[4], typeof(T5)); var v6 = (T6)Convert.ChangeType(inputs[5], typeof(T6)); var v7 = (T7)Convert.ChangeType(inputs[6], typeof(T7)); return (v1, v2, v3, v4, v5, v6, v7); } public static (T1, T2, T3, T4, T5, T6, T7, T8) ReadValue(this TextReader reader, char separator = ' ') { var inputs = ReadStringArray(reader, separator); var v1 = (T1)Convert.ChangeType(inputs[0], typeof(T1)); var v2 = (T2)Convert.ChangeType(inputs[1], typeof(T2)); var v3 = (T3)Convert.ChangeType(inputs[2], typeof(T3)); var v4 = (T4)Convert.ChangeType(inputs[3], typeof(T4)); var v5 = (T5)Convert.ChangeType(inputs[4], typeof(T5)); var v6 = (T6)Convert.ChangeType(inputs[5], typeof(T6)); var v7 = (T7)Convert.ChangeType(inputs[6], typeof(T7)); var v8 = (T8)Convert.ChangeType(inputs[7], typeof(T8)); return (v1, v2, v3, v4, v5, v6, v7, v8); } } } #endregion