co-relation analysis in C

/* Correlation Analaysis */
#include<stdio.h>
#include<string.h>
#include<math.h>

char tolower(char c)
{
    if(c>='A' && c<='Z')return c+'a';
}

int main()
{

    while(1){
    char Item1[10];
    char Item2[10];
    /*printf("Give Item1 Name: \n");*/
    scanf("%s",&Item1);
    /*printf("Give Item2 Name: \n");*/
    scanf("%s",&Item2);
    printf("\n");
    int a,b,c,d,sum1=0,sum2=0,sum3=0,sum4=0,Total=0;
    /*printf("Type the amount of %s",Item1);printf(" & %s \n",Item2);*/
    scanf("%d",&a);
    /*printf("Type the amount of %s",Item1);printf(" & not %s \n",Item2);*/
    scanf("%d",&b);
    /*printf("Type the amount of not %s",Item1);printf(" & %s \n",Item2);*/
    scanf("%d",&c);
    /*printf("Type the amount of not %s",Item1);printf(" & not %s \n",Item2);*/
    scanf("%d",&d);
    sum1=a+b;
    sum2=c+d;
    sum3=a+c;
    sum4=b+d;
    Total=sum1+sum2;
    printf("\n");
    printf("  Table 1: A 2x2 Contingency table with respect to "); printf("%s & %s",Item1,Item2);printf(" purchase \n");
    printf("  ----------------------------------------------------\n");
    printf("\t \t %s",Item2);printf("\t \t'%s",Item2);printf("\t \t Erow \n");
    printf("  ----------------------------------------------------\n");
    printf("\n");
    printf("  %s",Item1);printf("\t \t %d",a);printf(" \t \t %d",b);printf(" \t \t %d \n",sum1);
    printf("\n");
    printf(" '%s",Item1);printf("\t \t %d",c);printf(" \t \t %d",d);printf(" \t \t %d \n",sum2);
    printf("  ----------------------------------------------------\n");
    printf("  Ecol");printf("\t \t %d",sum3);printf(" \t \t %d",sum4);printf(" \t \t %d \n",Total);

    printf("\n");
    printf("\n");
    printf("  Total transaction= %d \n",Total);
    printf("\n");
    printf("  Burger: %d \n",sum1);
    printf("\n");
    printf("  Hotdog: %d \n",sum3);
    printf("\n");
    printf("  Burgur & Hotdog Both: %d \n",sum4);
    printf("\n");

    float e,f,g,L,min_sup,min_conf,sup,conf,all_conf,cosine;
    printf("  Enter Minimum Support:");
    scanf("%f",&min_sup);
    printf("  Enter Minimum Confidence:");
    scanf("%f",&min_conf);
    sup=(float (sum4)/float (Total));
    conf=(float (sum4)/float (sum3));
    printf("\n");
    printf("  SUPPORT: %.1f \n",sup);
    printf("\n");
    printf("  CONFIDENCE: %.2f \n",conf);

    double e1,e2,e3,e4;
    double  X2=0.00;

    e1=(sum1*sum3)/Total;
    e2=sum1-e1;
    e3=sum3-e1;
    e4=sum2-e3;

    printf("\n");
    printf("\n");
    printf("  Table 2: After Calculate the Expected Values.........\n");
    printf("\n");
    printf("  ----------------------------------------------------\n");
    printf("\t \t %s",Item2);printf("\t \t'%s",Item2);printf("\t \t Erow \n");
    printf("  ----------------------------------------------------\n");
    printf("\n");
    printf("  %s",Item1);printf("\t \t %d",a);printf(" [%.0lf",e1);printf("]");printf(" \t %d",b);printf(" [%.0lf",e2);printf("]");printf(" \t %d \n",sum1);
    printf("\n");
    printf(" '%s",Item1);printf("\t \t %d",c);printf(" [%.0lf",e3);printf("]");printf(" \t %d",d);printf(" [%.0lf",e4);printf("]");printf(" \t %d \n",sum2);
    printf("  ----------------------------------------------------\n");
    printf("  Ecol");printf("\t \t %d",sum3);printf(" \t \t %d",sum4);printf(" \t \t %d \n",Total);

    X2=((a-e1)*(a-e1))/e1+((b-e2)*(b-e2))/e2+((c-e3)*(c-e3))/e3+((d-e4)*(d-e4))/e4;
    printf("\n");
    printf("  Correlation Analysis X2 = %.2lf",X2);
    printf("\n");
    printf("\n");

    if (sup >min_sup && conf >min_conf){
        printf("  Strong Association Rule \n");
    }
    else {
        printf("  Not Strong Association Rule \n");
    }

    printf("\n");

    e=(float (sum4)/float (Total));
    f=(float (sum1)/float (Total));
    g=(float (sum3)/float (Total));
    L=e/(f*g);
    printf("  Lift is %.2f \n",L);
    if (L>1){printf("  Positively Correlated \n");}
    else if (L<1){printf("  Negatively Correlated \n");}
    else {printf("  Independent \n");}

    printf("\n");

    if(float (sum1) > float(sum3)){
    all_conf=(float (sum4)/float (sum1));}
    else
    {all_conf=(float (sum4)/float (sum3));}

    printf("  All_Conf(x) is %.3f \n",all_conf);
    if (all_conf>.5){printf("  Positively Correlated \n");}
    else if (all_conf<.5){printf("  Negatively Correlated \n");}
    else {printf("  Independent \n");}

    printf("\n");

    cosine=(float (sum4)/sqrt(float (sum1) * float (sum3)));
    printf("  cosine(H,B) is %.2f \n",cosine);
    if (cosine>.5){printf("  Positively Correlated \n");}
    else if (cosine<.5){printf("  Negatively Correlated \n");}
    else {puts("  Independent \n");}

    puts("-----------------X-----------------");
        char ch;

        while(tolower(ch)!='y'||tolower(ch)!='n')
        {
            puts("\n\nDo you want to continue? (press Y/y for YES or N/n for NO)");
            getchar();
            scanf("%c",&ch);


            if(tolower(ch)=='n'){puts("So, see you again. (o.o)");goto end;}
            else if(tolower(ch)=='y'){puts("Ok lets fun again. :D");puts("___________________________________________________________\n");break;}
        }

    }
    end:
    printf("\n");
    printf("Developed By Zobayer Alam Pantho, ID:08092103012, Intake:11, Dept; Department of Computer Science and Engineering, BUBT");
    printf("\n");
    printf("\n");
return 0;
}