字符串中的正整数，求解

Question

按照题目中的要求输入，输出的结果显示是对的，但是提交后报错输出格式错误，麻烦解答一下，或者直接把代码甩我脸上也行，求。

#include <iostream>

using namespace std;

int main()
{
    string sentence;
    cin >> sentence;

    int length=sentence.length();
    int a=0,b=0;
    for(int i=0; i<length; i++)
    {
        if(int(sentence[i])>='0'&&int(sentence[i])<='9')
        {
            cout << sentence[i];
            a=0;
            b++;
        }
        else
        {
            a++;
            if(a==1)
                cout <<endl;
        }
    }
    if(b==0)
        cout << "None";
    return 0;
}

Answer 1

#include <stdio.h>
#include <stdlib.h>

 
int main(void)
{
    char str[128] = {0x00};
    char num_str[100][32] = {0x00};
    int index = 0;
    int i = 0;
    int flag = 0;
    char * p = str;
    scanf("%s", str);
    for(; *p != '\0'; p++)
    {
        if(*p >= '0' && *p <= '9')
        {
            if(flag == 0)
            {
                flag = 1;
                num_str[index][i++] = *p;
            }else{
                num_str[index][i++] = *p;
            }
        }else{
            if(flag == 1)
            {
                flag = 0;
                index++;
                i = 0;
            }
        }   
    }
    if(flag == 1)
    {
        flag = 0;
        index++;
        i = 0;
    }
    if(index == 0)
    {
        printf("None\n");
    }
    for(int j = 0; j<index; j++)
    {
        printf("%s\n", num_str[j]);
    }
    return 0; 
}