數字到英文描述的轉換

1.給定一個整數，列印該整數的對應的英文描述，例如輸入1234，輸出“One Thousand，Two Hundred Thirty Four”

解題思路：

例如在轉換19323984時，我們可以考慮分段處理，每三位轉換一次，並在適當的位置插入”Thousand”和”million”,也即convert(19 323 984)=conver(19)+” million “+convert(323)+” thousand “+convert(984)

#include<iostream>
#include<string>
using
 
 namespace std;
string digits[]={"One","Two","Three","Four","Five","Six","Seven","Eight","Nine"};
string teens[]={"Eleven","Twelve","Thirteen","Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"};
string tens[]={"Ten","Twenty","Thirty","Fourty","Fifty","Sixty","Seventy","Eighty","Ninety"
 
};
string bigs[]={"","Thousand","Million","Billion"};

string numToString100(int number)
{
    string str="";
    //轉換百位的地方
    if(number>100)
    {
        str+=digits[number/100-1]+" Hundred ";
        number%=100;
    }
    //轉換十位的地方
    if(number>=11 && number<=19)
    {
        str+=teens[number-11
 
]+" ";
    }
    else if(number==10 || number>=20)
    {
        str+=tens[number/10-1]+" ";
        number%=10;
    }
    if(number>=1 && number<=9)
    {
        str+=digits[number-1]+" ";
    }
    return str;
}
string numToString(int number)
{
    if(number==0)
    {
        return "Zero";
    }
    else if(number<0)
    {
        return "Negative"+numToString(-1*number);
    }

    int count=0;
    string str="";
    while(number>0)
    {
        if(number%1000 != 0)
        {
            str=numToString100(number%1000)+bigs[count]+" "+str;
        }
        number/=1000;
        count++;
    }
    return str;
}
int main()
{
    int number;
    cin>>number;
    string result;
    result=numToString(number);
    cout<<result<<endl;
}

程式執行結果：

2.拼音轉換為數字

將中文數字的拼音字元轉為最終的數字，每個字拼音的首字母大寫，比如:JiuWanJiuQianJiuBaiJiuShiJiu表示九萬九千九百九十九，即阿拉伯數字99999.

你當然就得每個數字的漢語拼音，但是還是提示你一下，Ling、Yi、Er、San、Si、Wu、Liu、Qi、Ba、Jiu、Shi、Bai、Qian、Wan。

為了簡單起見，我們要處理的數字在萬以內，不含負數，十、百、千、萬等單位前面一定有數字，如YiShi表示10.

輸入：中文數字的拼音字串

輸出：阿拉伯數字

樣例輸入：SanBaiLingSan

樣例輸出：303

解題思路：

首先遍歷輸入的拼音字串，根據拼音首字母大寫其他字母小寫的特點，將拼音字元分離出來，再與拼音字元表進行比較，將其轉換成數字和對應單位的值

需要注意的是
1.對於最後一個輸入字串中的最後一個字母要做特殊處理，防止出現死迴圈，方法是變數i++;
2.要用一個變數來儲存單位前面的數字，如果得到的是單位，則需要將之前儲存的乘以相應的單位再相加
3.在result += flag*number;之後要將 flag=0;否則會比如輸入YiShi，程式輸出是11，凡是以Shi、Bai、Qian、Wan結尾的拼音，都會出錯。（根據反饋，修復該Bug）

#include<iostream>
#include<string>
#include<cctype>
using namespace std;

string num[14] = { "Ling", "Yi", "Er", "San", "Si", "Wu", "Liu", "Qi", "Ba", "Jiu", "Shi", "Bai", "Qian", "Wan" };
int getNum(string str)
{
    //cout<<str<<endl;
    int ret=0,n=0;
    for (int i = 0; i < 14; i++)
    {
        if (num[i] == str)
        {
            ret = i;
            break;
        }
    }
    if (ret >10)
    {
        n = ret;
        ret = ret / 10;
        for (int i = 0; i < n % 10 + 1; i++)
        {
            ret *= 10;
        }
    }
    return ret;
}
int main()
{
    string str, temp;
    cin >> str;
    int len = str.size();
    int result = 0, begin = 0, flag = 0, number;
    for (int i = 0; i < len; i++)
    {

        if (begin == 0 || islower(str[i]) && i != len - 1)
        {
            temp.push_back(str[i]);
            begin = 1;
        }
        else
        {
            if (i == len - 1)
            {
                temp.push_back(str[i]);
                i++;    //因為後面i要減1，否則會進入死迴圈
            }
            number = getNum(temp);
            if (number >= 0 && number <= 9)
            {
                flag = number;
            }
            else
            {
                result += flag*number;
                flag = 0;
            }
            temp.erase();
            i--;
            begin = 0;
        }
    }
    result += flag;
    cout << result << endl;
}

程式執行結果：