[day_030420] find the longest consecutive number string in the string

Find the longest consecutive number string in the string

Title source

Cattle from ： Find the longest consecutive number string in the string

Title Description

Read in a string str, Output string str The longest consecutive number string in

Input description

Each test input contains 1 Test cases , A string str, Length not exceeding 255.

Output description

Output... In one line str The longest consecutive number string in .

Example 1

Input

abcd12345ed125ss123456789

Output

123456789

Thought analysis

• Traversal string , Use one cur Save the current continuous number string , use ret Save the current longest number string
• Each occurrence of a non numeric character represents a cur End of string , Compare the current cur And ret The length of
• After each comparison , Empty cur String content

Code display

#include<iostream>
#include<string>

using namespace std;
int main()
{
    
    string str;
    string cur;
    string ret;
    getline(cin, str);
    // The control condition of the outer cycle is <=, Otherwise, when the number string is at the end of the original string 
    // If the last number string found is the longest string , If the cycle condition is not satisfied, it will exit the cycle directly , No more assignments 
    for (int i = 0; i <= str.length(); i++)
    {
    
        // If the current character is a number , Then make a splice 
        if (isdigit(str[i]))
        {
    
            cur += str[i];
        }

        // Characters are non numeric , Is the current cur End of string 
        else
        {
    
            //string Initial after definition lenth by 0
            if (cur.length() > ret.length())
            {
    
            	// Find a longer string , Update string 
                ret = cur;
            }
            // After comparison cur And ret after , Yes cur Clear 
            cur.clear();
        }
    }
    cout << ret << endl;
    return 0;
}

summary

• isdigit() function , Determine whether the character is a numeric character
• clear() function , Empty the string contents