题解 | #人民币转换#

#include <iostream>
#include <string>
#include <map>
#include <vector>
#include <algorithm>
#include <list>
#include <set>
#include <cmath>
#include <cstring>
#include "stdlib.h"
#include <iomanip>
#include <unordered_map>
#include <stack>
#include <sstream>

using namespace std;

vector<string> gewei = { "零","壹","贰","叁","肆","伍","陆","柒","捌","玖" };
vector<string> jinwei = { "仟","佰","拾",""};
bool isTW(string s)
{
	int i = 0;
	while (i < s.length())
	{
		if (s[i] != '0')
			break;
		i++;
	}
	return (s.length()-i)%4 == 0;
}
bool isNotZ(string s)
{
	for (auto c : s)
		if (c != '0')
			return true;
	return false;
}
string read(string num)
{
	string res;
	if (num.length() >= 9)
	{
		string qian = read(num.substr(0, num.length() - 8));
		if (isTW(num.substr(num.length() - 8, 8)))
		{
			res = qian + "亿" + read(num.substr(num.length() - 8, 8));
		}
		else if(num[num.length() - 8] == '0')
			res = qian + "亿零" + read(num.substr(num.length() - 8, 8));
		else
			res = qian + "亿" + read(num.substr(num.length() - 8, 8));
	}
	else if (num.length() >= 5)
	{
		string qian = read(num.substr(0, num.length() - 4));
	
		if(num[num.length() - 4] == '0'&& isNotZ(num.substr(num.length() - 4, 4)))
			res = qian + "万零" + read(num.substr(num.length() - 4, 4));
		else
			res = qian + "万" + read(num.substr(num.length() - 4, 4));
	}
	else
	{
		if (!isNotZ(num))
			return "";
		for (int i = 0; i < num.length(); i++)
		{
			int dig = (4 - num.length() + i);
			if (i > 0 && num[i - 1] == '0'&&num[i]=='0')
				continue;
			if((dig!=2) || (num[i]!='1'))
				res = res+gewei[num[i] - '0'];
			if(num[i]!='0')
				res+= jinwei[dig];
			if (i==(num.length()-1)||stoi(num.substr(i + 1, num.length() - i - 1)) == 0)
				return res;
		}
	}
	return res;
}

int main()
{
	string s;
	cin >>s;
	string ans;
	int k = s.find('.');
	string zheng = s.substr(0, k);
	string xiao = s.substr(k + 1, 2);
	string ans1 = read(zheng);
	if (ans1.length() > 0)
		ans = "人民币" + ans1 + "元";
	else
		ans = "人民币";
	if (xiao == "00")
		ans += "整";
	else if (xiao[0] == '0')
		ans += gewei[xiao[1] - '0'] + "分";
	else if (xiao[1] == '0')
		ans += gewei[xiao[0] - '0'] + "角";
	else 
		ans += gewei[xiao[0] - '0'] + "角"+ gewei[xiao[1] - '0'] + "分";
		 

	cout << ans;
	return 0;
}