题解 | #字符串中找出连续最长的数字串#

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

bool isNum(char c)
{
    return c <= '9' && c >= '0';
}

int main() {
    string str;
    string retstr;
    string temp;
    cin >> str;
    size_t len = str.size();
    for (int i = 0; i <= len; i++)
    {
        if (isNum(str[i]))
        {
            temp += str[i];
        } 
        else
        {
            if (retstr.size() < temp.size())
                retstr = temp;
            else
                temp.clear();
        }
    }
    cout << retstr << endl;
    return 0;
}