1123.英语数字转换器

题目地址
描述
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
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
输出
输出将是每一个单独一行，每一个后面一个换行符

样例输入
six
negative seven hundred twenty nine
one million one hundred one
eight hundred fourteen thousand twenty two

样例输出
6
-729
1000101
814022

分析
million thousand hundred 其实是三个等级，利用递归可将各级数目相加得解，而利用map可以建立英语输入和实际数字的对应关系。
反思
大神写这题只用800k，而我写了1300k，实在是化简不了了。花的时间也不短，各种调试。又犯了不少低级错误如局部变量全局变量写两次，循环括号位置错误等等。

#include<iostream>
#include<map>
#include<string>
#include<vector>
using namespace std;
map<string,int> book; 
string abc[32]={"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"};
int mindex[3]={1000000,1000,100};
int num[32]={-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,
30,40,50,60,70,80,90,100,1000,1000000};
vector<int> result;  
int getn(int i,int j){     //按层次在第i和第j个数中计算和
    int ans=0;
    for(int p=0;p<3;++p){
        for(int k=i;k<=j;++k){
            if (result[k]==mindex[p]){
                ans+=getn(i,k-1)*mindex[p];
                i=k+1;
                break;
            }
        }
    }
    for(;i<=j;++i)ans+=result[i];
    return ans; 
}
int main(){
    for(int i=0;i<32;++i)
        book.insert(make_pair(abc[i],num[i]));
    while(1){
        bool flag=0;
        string s;
        getline(cin,s);     //直接输入字符串的函数getline()
        int len=s.size();
        if(len==0)break;
        int i=0,ans=0;
            for(int j=1;j<=len;++j)
                if(s[j]==' '||j==len){
                    result.push_back(book[s.substr(i,j-i)]);
                    i=j+1;
                    j+=2;
                }   
        if(result[0]==-1){
            flag=1;
            result.erase(result.begin(),result.begin()+1);
            --len;
        }
        if(flag)cout<<'-';
        cout<<getn(0,result.size()-1)<<endl;
        result.clear();
    }
}