Challenge accepted Mr.pankaj banwari

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<conio.h>
#define pf printf
#define sf scanf_s
int begins(char s[],char t[])
{
    int i,z=0,count=0;
    for(i=0;i<strlen(t);i++)
        if(s[i]==t[i])
            count++;
    if(count==strlen(t))
        z=1;
    return z;
}
int beginsor(char s[],char t[],char u[])
{
    int z=0,i,k;
    i = begins(s,t);
    k = begins(s,u);
    if(i==1||k==1)
        z=1;
    return 1;
}
int notbegins(char s[],char t[])
{
    int z=0,i;
    i = begins(s,t);
    if(i==0)
        z=1;
    return z;
}
int ends(char s[],char t[])
{
    int i,k=0,slen,z=0,count=0;
    slen = strlen(s)-strlen(t);
    for(i=slen;i<strlen(s);i++)
    {
        if(s[i]==t[k])
            count++;
        k++;
    }
    if(count==strlen(t))
        z=1;
    return z;
}
int endsor(char s[],char t[],char u[])
{
    int z=0,i,k;
    i = ends(s,t);
    k = ends(s,u);
    if(i==1||k==1)
        z=1;
    return 1;
}
int notends(char s[],char t[])
{
    int z=0,i;
    i = ends(s,t);
    if(i==0)
        z=1;
    return z;
}
int contains(char s[],char t[])
{
    int i,j,k=0,z=0,count=0;
    for(i=0;i<strlen(s);i++)
    {
        if(s[i]==t[k])
        {
            for(j=k;j<(strlen(t)-1);j++)
            {
                if(s[++i]=t[j])
                    count++;
            }
        }
    }
    if(count==(strlen(t)-1))
        z=1;
    return z;
}
int notcontains(char s[],char t[])
{
    int z=0,i;
    i = contains(s,t);
    if(i==0)
        z=1;
    return z;
}
int beginandend(char s[],char t[],char u[])
{
    int i,j,z=0;
    i = begins(s,t);
    j = ends(s,u);
    if(i==1&&j==1)
        z=1;
    return z;
}
int doesnotbeginandend(char s[],char t[],char u[])
{
    int z=0,i;
    i = beginandend(s,t,u);
    if(i==0)
        z=1;
    return z;
}
int main()
{
    char s[100],t[100],u[100];
    int ch,z;
    pf("Enter string 1 \n");
    gets_s(s);
    pf("\nEntered string is given below\n");
    pf("%s",s);
    while(1)
    {
        pf("\n\n\nEnter choice \n1.Set of strings begins with ?\n2.Set of strings doesn't begins with ?");
        pf("\n3.Set of strings that end with ?\n4.Set of strings that doesn't end with ?\n5.Set of strings that contains ?");
        pf("\n6.Set of strings that doesn't contains ?\n7.Set of strings that starts with ? and ends with ?");
        pf("\n8.Set of strings that doesn't starts with ? and ends with ?");
        pf("\n9.Set of strings that begins with ? or ?");
        pf("\n10.Set of strings that ends with ? or ?\n11.Exit\n");
        sf("%d",&ch);
        if(ch==11)
            break;
        z=0;
        switch(ch)
        {
            case 1:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = begins(s,t);
                    break;
            case 2:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = notbegins(s,t);
                    break;
            case 3:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = ends(s,t);
                    break;
            case 4:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = notends(s,t);
                    break;
            case 5:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = contains(s,t);
                    break;
            case 6:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    z = notcontains(s,t);
                    break;
            case 7:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    pf("Enter string 3\n");
                    scanf_s("%s",u);
                    z = beginandend(s,t,u);
                    break;
            case 8:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    pf("Enter string 3\n");
                    scanf_s("%s",u);
                    z = doesnotbeginandend(s,t,u);
                    break;
            case 9:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    pf("Enter string 3\n");
                    scanf_s("%s",u);
                    z = beginsor(s,t,u);
                    break;
            case 10:pf("Enter string 2\n");
                    scanf_s("%s",t);
                    pf("Enter string 3\n");
                    scanf_s("%s",u);
                    z = endsor(s,t,u);
                    break;
            default:pf("\nInvalid input");
        }
        if(z==1)
                pf("\nEntered string will be accepted by the Machine");
        else
                pf("\nEntered string will not be accepted by the Machine");
    }
    _getch();
    return 0;
}