数组越界，找不到错误

Question

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{
    char a[100],b[100];
    int i = 0,len,k=0;
    while ((a[i] = getchar()) != '\n')
    {
        i++;
    }
    a[i + 1] = '\0';
    len = i;
    for (i = 0; i < len; i++)
    {
        if (a[i] == 'a' || a[i] == 'e' || a[i] == 'i' ||
            a[i] == 'u' || a[i] == 'o')
        {
            b[k++] = a[i];
        }
    }
    b[k + 1] = '\0';
    for (i = 0; i < k; i++)
    {
        cout << b[i];
    }
    return 0;
}

Answer 1

第 13 行改为a[i] = 0;
第23行改为b[k] =0;
另外第9行要保证输入字符个数小于100个，不能等于100