ALDS1_3_A: Stack

問題へのリンク

C#のソース

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

// Q007 スタック https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_3_A&lang=jp
class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("1 2 + 3 4 - *");
            //-3
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        string[] RPNArr = InputList[0].Split(' ');

        var Stk = new Stack<int>();

        foreach (string EachStr in RPNArr) {
            if (EachStr == "+" || EachStr == "-" || EachStr == "*") {
                int exp2 = Stk.Pop();
                int exp1 = Stk.Pop();

                if (EachStr == "+") Stk.Push(exp1 + exp2);
                if (EachStr == "-") Stk.Push(exp1 - exp2);
                if (EachStr == "*") Stk.Push(exp1 * exp2);
                continue;
            }
            Stk.Push(int.Parse(EachStr));
        }
        Console.WriteLine(Stk.Pop());
    }
}

解説

Stackジェネリックを使ってます。