title: DFA is not accepting strings
body: <p>my program is supposed to implement a dfa for a binary string... dfa is a machine that can be in only one state at a time (when you enter a string the machine should use it and at the last step it should reach to the final state. if so, we say that string is accepted by the machine) ... 
  this machine works this way:</p>
  
  <p>at first program asks the number of states, if u consider my pic, u see that it has 3 states(q0,q1,q2) so we enter 3. then it asks about the number of inputs. my inputs are 0,1 so I enter 2... then it asks to enter the inputs, we enter 0 then 1! then it asks the number of final states, the final state here is only q1... so we enter it... then u see this: (q0,0) = q  it means q0 goes to which state with 0... for example here q0 goes to q0 with 0 ... others are like that. after filling this part, we enter the sring and it would say if string is valid or not</p>
  
  <p>here is the code:</p>
  
  <pre><code>   #include&lt;stdio.h&gt;
  #include&lt;conio.h&gt;
  
  int ninputs;
  
  int check(char,int ); //function declaration
  int dfa[10][10];
  char c[10], string[10];
  
  int main()
  {
       int nstates, nfinals;
       int f[10];
       int i,j,s=0,final=0;
       printf("enter the number of states that your dfa consist of \n");
       scanf("%d",&amp;nstates); // 3
       printf("enter the number of input symbol that dfa have \n");
       scanf("%d",&amp;ninputs); // 2
       printf("\nenter input symbols\t");
  
       for(i=0; i&lt;ninputs; i++) 
       {
             printf("\n\n %d input\t", i+1);
             printf("%c",c[i]=getch()); // 01
       }
  
       printf("\n\nenter number of final states\t");
       scanf("%d",&amp;nfinals); // 1
  
       for(i=0;i&lt;nfinals;i++)
       {
            printf("\n\nFinal state %d : q",i+1);
            scanf("%d",&amp;f[i]); // 1
       }
  
       printf("-----------------------------------------------------------------------");
       printf("\n\ndefine transition rule as (initial state, input symbol ) = final state\n");
  
       for(i=0; i&lt;ninputs; i++)
       {
            for(j=0; j&lt;nstates; j++)
            {
                 printf("\n(q%d , %c ) = q",j,c[i]);
                 scanf("%d",&amp;dfa[i][j]);
                 // q(0,0)=0
                 // q(1,0)=0
                 // q(2,0)=2
                 // q(0,1)=1
                 // q(1,1)=2
                 // q(2,1)=1
            }
       }
  
       do
       {
            i=0;
            printf("\n\nEnter Input String.. ");
            scanf("%s",string);  // 01
  
            while(string[i]!='\0')
            {
                if((s=check(string[i++],s))&lt;0)
                    break;
                for(i=0 ;i&lt;nfinals ;i++)
                {
                    if(f[i] ==s )
                        final=1;
                    if(final==1)
                        printf("\n valid string"); 
                    else
                        printf("invalid string");
                    getch();
  
                    printf("\nDo you want to continue.?  \n(y/n) ");
                }
            }
       }
       while(getch()=='y');
  
       getch();
  }
  int check(char b,int d)
  {
       int j;
       for(j=0; j&lt;ninputs; j++)
           if(b==c[j])
               return(dfa[d][j]);
       return -1;
  }
  </code></pre>
  
  <p>the problem is that when I enter my string, the program says it's invalid, however it should be accepted by the machine... for example consider the machine in the photo and test this string on it: 01</p>
  
  <p><img src="https://i.stack.imgur.com/ycfEZ.jpg" alt="enter image description here"></p>
  
  <p>so what's wrong with the code?</p>