[算法练习] 英语数字转换器

题目说明：

在这个问题中，将用英语给你一个或多个整数。你的任务是将这些数字转换成整型表示。数字范围从-999,999,999到999,999,999.下面是你的程序必须考虑的详尽的英语单词表：

negative, zero, one, two, three, four,five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen,fifteen, sixteen, seventeen, eighteen, nineteen, twenty, thirty, forty, fifty,sixty, seventy, eighty, ninety, hundred, thousand, million

输入包括多个样例，注意：

1.负数前面有词negative

2.当能用thousand的时候，将不用hundred。例如1500将写为"one thousand five hundred",而不是"fifteen hundred".

输入将以一个空行结束

程序代码：

#include <gtest/gtest.h>
#include <iostream>
#include <string>

using namespace std;

enum TOKEN_TYPE
{
    TYPE_NUMBER,
    TYPE_UNIT,
    TYPE_NEGATIVE
};

struct Token
{
    string        StringValue;
    int            Value;
    TOKEN_TYPE    Type;
};

Token sTokenTable[] =
{
    {"zero",        0, TYPE_NUMBER},
    {"one",            1, TYPE_NUMBER},
    {"two",            2, TYPE_NUMBER},
    {"three",        3, TYPE_NUMBER},
    {"four",        4, TYPE_NUMBER},
    {"five",        5, TYPE_NUMBER},
    {"six",            6, TYPE_NUMBER},
    {"seven",        7, TYPE_NUMBER},
    {"eight",        8, TYPE_NUMBER},
    {"nine",        9, TYPE_NUMBER},
    {"ten",            10, TYPE_NUMBER},
    {"eleven",        11, TYPE_NUMBER},
    {"twelve",        12, TYPE_NUMBER},
    {"thirteen",    13, TYPE_NUMBER},
    {"fourteen",    14, TYPE_NUMBER},
    {"fifteen",        15, TYPE_NUMBER},
    {"sixteen",        16, TYPE_NUMBER},
    {"seventeen",    17, TYPE_NUMBER},
    {"eighteen",    18, TYPE_NUMBER},
    {"nineteen",    19, TYPE_NUMBER},
    {"twenty",        20, TYPE_NUMBER},
    {"thirty",        30, TYPE_NUMBER},
    {"forty",        40, TYPE_NUMBER},
    {"fifty",        50, TYPE_NUMBER},
    {"sixty",        60, TYPE_NUMBER},
    {"seventy",        70, TYPE_NUMBER},
    {"eighty",        80, TYPE_NUMBER},
    {"ninety",        90, TYPE_NUMBER},
    {"hundred",        100, TYPE_UNIT},
    {"thousand",    1000, TYPE_UNIT},
    {"million",        1000000, TYPE_UNIT},
    {"negative",    -1, TYPE_NEGATIVE}
};

bool GetPreToken(const string& value, int& pos, Token& nextToken)
{
    bool bRetValue = false;
    pos = value.find_last_not_of(" ", pos);
    if (pos == string::npos)
    {
        return false;
    }

    string tokenStr;
    string::size_type next = value.rfind(" ", pos);
    if (next != string::npos)
    {
        tokenStr = value.substr(next+1, pos-next);
    }
    else
    {
        tokenStr = value.substr(0, pos+1);
    }

    for (int i=0; i<sizeof(sTokenTable)/sizeof(sTokenTable[0]); ++i)
    {
        if (tokenStr.compare(sTokenTable[i].StringValue)==0)
        {
            nextToken.Type = sTokenTable[i].Type;
            nextToken.Value = sTokenTable[i].Value;

            bRetValue = true;
            pos = next;
            break;
        }
    }

    return bRetValue;
}

long Parse(const string& value)
{
    long lResult = 0;
    int nNegatvie = 1;
    int nPos = string::npos;
    Token NextToken;
    int CurrentUnitValue = 1;    

    while (GetPreToken(value, nPos, NextToken))
    {
        switch (NextToken.Type)
        {
        case TYPE_NEGATIVE:
            nNegatvie = -1;
            break;

        case TYPE_NUMBER:
            lResult += NextToken.Value * CurrentUnitValue;
            break;

        case TYPE_UNIT:

            if (NextToken.Value >= CurrentUnitValue)
            {
                CurrentUnitValue = NextToken.Value;
            }
            else
            {
                CurrentUnitValue *= NextToken.Value;
            }
            break;
        }

        if (nPos == string::npos)
        {
            break;
        }
    }

    lResult *= nNegatvie;

    return lResult;
}

int main2()
{
    char input[512];
    cin.getline(input,512);
    string value(input);
    while (!value.empty())
    {
        cout << Parse(value) << endl;
        cin.getline(input, 512);
        value = input;
    }

    return 0;
}

// http://dsalgo.openjudge.cn/201409week4/1/?lang=zh_CN

// Test Case
// zero
// six
// negative seven hundred twenty nine
// one million one hundred one
// eight hundred fourteen thousand twenty two
// eight thousand fourteen hundred  twenty two

TEST(BaiLian, tEnglishNumberTranslator)
{
    //main2();

    ASSERT_EQ(Parse("zero"), 0);
    ASSERT_EQ(Parse("six"), 6);
    ASSERT_EQ(Parse("negative seven hundred twenty nine"), -729);
    ASSERT_EQ(Parse("one million one hundred one"), 1000101);
    ASSERT_EQ(Parse("eight hundred fourteen thousand twenty two"), 814022);
    ASSERT_EQ(Parse("one"), 1);
    ASSERT_EQ(Parse("two"), 2);
    ASSERT_EQ(Parse("three"), 3);
    ASSERT_EQ(Parse("four"), 4);
    ASSERT_EQ(Parse("five"), 5);
    ASSERT_EQ(Parse("seven"), 7);
    ASSERT_EQ(Parse("eight"), 8);
    ASSERT_EQ(Parse("nine"), 9);
    ASSERT_EQ(Parse("ten"), 10);
    ASSERT_EQ(Parse("eleven"), 11);
    ASSERT_EQ(Parse("twelve"), 12);
    ASSERT_EQ(Parse("thirteen"), 13);
    ASSERT_EQ(Parse("fourteen"), 14);
    ASSERT_EQ(Parse("fifteen"), 15);
    ASSERT_EQ(Parse("sixteen"), 16);
    ASSERT_EQ(Parse("seventeen"), 17);
    ASSERT_EQ(Parse("eighteen"), 18);
    ASSERT_EQ(Parse("nineteen"), 19);
    ASSERT_EQ(Parse("twenty"), 20);
    ASSERT_EQ(Parse("thirty"), 30);
    ASSERT_EQ(Parse("forty one"), 41);
    ASSERT_EQ(Parse("fifty"), 50);
    ASSERT_EQ(Parse("sixty"), 60);
    ASSERT_EQ(Parse("seventy seven"), 77);
    ASSERT_EQ(Parse("eighty"), 80);
    ASSERT_EQ(Parse("ninety"), 90);
    ASSERT_EQ(Parse("one hundred three"), 103);
    ASSERT_EQ(Parse("negative one hundred twenty three million four hundred fifty six thousand seven hundred eighty"), -123456780);
    ASSERT_EQ(Parse("one hundred twenty three million four hundred fifty six thousand seven hundred eighty"), 123456780);
    ASSERT_EQ(Parse("nine hundred ninety nine million nine hundred ninety nine thousand nine hundred ninety nine"), 999999999);
    ASSERT_EQ(Parse("negative nine hundred ninety nine million nine hundred ninety nine thousand nine hundred ninety nine"), -999999999);
}