dfa.c

#include<stdio.h>
#include<string.h>
int checkState(char ele[20][20],char array[50][3],int arrlength){
	int i;
	for(i=0;i<arrlength;i++)
		if(strcmp(ele[0],array[i]) ==0)
			return i;
	return -1;
}
void main(){
	int symbolsNo,statesNo,i,j,start=0,end=0,test=0,count=0,finalNo;
	char states[50][3],symbols[50][3],str[50][50][10],id[50],temp[20][20],final[50][3],temp1[20][20];
	printf("Enter no of tests u want to perform:\n");
	scanf("%d",&test);
	printf("Enter number of states:\n");
	scanf("%d",&statesNo);
	printf("Enter number of symbols\n");
	scanf("%d",&symbolsNo);
	printf("Enter names of the states [start state - final state]\n");
	for(i=0;i<statesNo;i++)
		scanf("%s",states[i]);
	printf("Enter names of the symbols\n");
	for(i=0;i<symbolsNo;i++)
		scanf("%s",symbols[i]);
	printf("Enter transitions below:\n");
	for(i=0;i<statesNo;i++){
		for(j=0;j<symbolsNo;j++){
			printf("( %s , %s ) = " ,states[i],symbols[j]);
			scanf("%s",str[i][j]);
		}
	}
	printf("Enter number of final states:\n");
	scanf("%d",&finalNo);
	printf("Enter final states:\n");
	for(i=0;i<finalNo;i++)
		scanf("%s",final[i]);
	while(test != 0){
		printf("\n\nEnter instantaneous discription to test the validity\n");
		scanf("%s",id);
		count = strlen(id);
		start =0;
		for(i=0;i < count;i++){
		    temp1[0][0] = id[i];
			end =checkState(temp1[0],symbols,symbolsNo);
			if(end == -1)
				break;
			strcpy(temp[0],str[start][end]);
			start = checkState(temp,states,statesNo);
			if(start == -1)
				break;
		}
		if(i != count || checkState(temp,final,finalNo) == -1)
			printf("Entered an invalid id");
		else
			printf("Entered a valid id");
		test--;
	}
}