AFN to AFD v0.02

#include<stdio.h>
#define MAX_STRLEN 256
#define SIN_TIPO float


/*Source code from the web and Uriel Cambrón Hernández*/

int main() {
    SIN_TIPO afd[20][20];
    char a_1[MAX_STRLEN];
    char b[MAX_STRLEN];
    int con;
    int i;
    int j;
    int k;
    float l;
    int opc;
    char x[MAX_STRLEN][10][10];
    for (i=1;i<=10;i+=1) {
        for (j=1;j<=10;j+=1) {
            x[i][j]="0";
        }
    }
    do {
        printf("Menu\n");
        printf("1.-Input nodes\n");
        printf("2.-Input tags\n");
        printf("3.-Input unions\n");
        printf("4.-Show AFN Lenguaje\n");
        printf("5.-Get AFD\n");
        printf("6.-Get Regular Expresion\n");
        printf("7.-Exit\n");
        do {
            scanf("%i",&opc);
        } while (!(opc==1 || opc==2 || opc==3 || opc==4 || opc==6 || opc==5 || opc==7));
        switch (opc) {
        case 1:
            printf("¿How many nodos? (1-10)?:  ");
            scanf("%i",&k);
            k=k+1;
            for (i=2;i<=k;i+=1) {
                j=1;
                printf("Write nodos: %f",i-1);
                scanf("%s",x[i][j]);
            }
            break;
        case 2:
            printf("¿How many tags?(1-10)?:  ");
            scanf("%f",&l);
            l=l+1;
            for (i=2;i<=l;i+=1) {
                j=1;
                printf("Write tags:  %f",i-1);
                scanf("%s",x[j][i]);
            }
            break;
        case 3:
            con=1;
            for (i=2;i<=k;i+=1) {
                for (j=2;j<=l;j+=1) {
                    printf("¿What nodo(s) points %s in the tag %s?:  ",x[i][j-con],x[1][j]);
                    scanf("%s",x[i][j]);
                    con=con+1;
                }
                con=1;
            }
            for (i=1;i<=k;i+=1) {
                for (j=1;j<=l;j+=1) {
                    printf("%s  ",x[i][j]);
                }
                printf(" \n");
            }
            break;
        case 4:
            a_1=x[2][1];
            b=x[k][1];
            printf("¿Where is the inicial node?  ");
            scanf("%s",a_1);
            printf("¿What is the final node?
            printf("L(A)=(");
            printf("{");
            for (i=2;i<=k;i+=1) {
                printf("[%s],",x[i][1]);
            }
            printf("},E,{");
            for (j=2;j<=l;j+=1) {
                printf("%s,",x[1][j]);
            }
            printf("},%s,%s)\n",a_1,b);
            break;
        case 5:
            printf("%s\n",a_1);
            break;
        case 6:
            printf("%s\n",a_1);
            break;
        }
    } while (opc!=7);
    return 0;
}