Write a program to identify whether a binary series is valid or not following a condition ( condition: even 0's and odd 1's )

 

#include<iostream>
#include<cstdio>
#include<cstring>

using namespace std;

int main()
{
    int table[4][2]={{3,1},{2,0},{1,3},{0,2}};

    int state=0, check=1, i;

    char str[100];

    cout<<"Enter a String : ";

    gets(str);

    for(i=0; i<strlen(str); i++)

    {

        if(str[i]=='0')

            state=table[state][0];

        else if(str[i]=='1')

            state=table[state][1];

        else

            check=0;

    }

    if(state==1 && check==1)

        cout<<"This is a valid string";
    else
        cout<<"This is not a valid string";
    return 0;
}

Sample input: 

Enter a String : 1000

Sample output:

This is not a valid string