C++分离字符串中的数字和字符 转

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

void part(string _str, vector<int> &_num, vector<char> &_op)
{
    int sum = 0;
    unsigned int i = 0;

    while (i < _str.length())
    {
        if (‘0‘ <= _str.at(i) && _str.at(i) <= ‘9‘)
            //还原连续的数字
            sum = sum * 10 + (_str.at(i) - ‘0‘);
        else
        {
            _num.push_back(sum);
            _op.push_back(_str.at(i));
            sum = 0;
        }
        i++;
    }

    //判断最后一个字符是否是数字
    if (0 != sum)
        _num.push_back(sum);
}

int main()
{
    vector<int> num(0);
    vector<char> op(0);
    string str;

    cin >> str;
    part(str, num, op);

    //输出测试
    for (unsigned int i = 0; i < num.size(); i++)
        cout << num.at(i) << " ";
    cout << endl;
    for (unsigned int i = 0; i < op.size(); i++)
        cout << op.at(i) << " ";

    return 0;
}