Question 13: Imagine you are developing a software package that requires users to enter their own passwords. Your software requires that users’ passwords meet the following criteria: • The password should be at least six characters long. • The password should contain at least one uppercase and at least one lowercase letter. • The password should have at least one digit. Write a program that asks for a password and then verifies that it meets the stated criteria. If it doesn’t, the program should display a message telling the user why.

Question 13:  Imagine you are developing a software package that requires users to  enter their own passwords. Your software requires that users’ passwords meet  the following criteria: 
• The password should be at least six characters long.
• The password should contain at least one uppercase and at least one lowercase  letter.



• The password should have at least one digit.  Write a program that asks for a password and then verifies that it meets the  stated criteria. If it doesn’t, the program should display a message telling the  user why.

/*
Name:                   Mudassar Ali
Roll:                   BCSF15M045   [Morning]
Assignment:             No# 05
Teacher:                Miss Sadia Shahzad
*/
#include <iostream>
#include <cstring>
using namespace std;
int main()
{
    cout<<"\t\tThis programme will you ask to enter password!!\n\n";
    char pass[20];      // Character array for storing the password.
    int Up[26]={0};     // counter for Upper_case letters.
    int Lo[26]={0};     // counter for Lower_case letters.
    int Nu[26]={0};     // counter for numbers [0-9].
    int s1=0,s2=0,s3=0; // sum variable for Up,Lo,Nu strings respectively.
    bool flag = false;  // Bool function to verify the input values only alphabets and digits only.

    cout<<"Enter your  password:"; // Getting input.
    cin.getline(pass,20);

    int len = strlen(pass);        // Length of string also find using loop.

    if(len>=6)                    // To valid or invalid the password.
    {
    for(int i = 0; pass[i]!='\0';i++)// Counter loop
    {
        if(pass[i]>= 'A' && pass[i]<='Z'||pass[i]>= 'a' && pass[i]<='z'||pass[i]>= '0' && pass[i]<='9') // Password must be between this condition.

        {
            if(pass[i]>= 'A' && pass[i]<='Z')   // counting upper letters.
            {
                Up[pass[i]-'A']++;              // counter for letters
            }
            else if(pass[i]>= 'a' && pass[i]<='z') // counting lower letters
            {
                Lo[pass[i]-'a']++;              // counter for letters.
            }
            else if(pass[i]>= '0' && pass[i]<='9') // counter for numbers o - 9
            {
                Nu[pass[i]-'0']++;
            }
        }// end of if

        else  // else part of if
        {
            flag = true;
        }//end of else
    }// end of for loop.

    if (flag) // true flag.
    cout<<"\nWarning!! Your password not contained @,/,1!,$,* etc !!";

    for(int x=0;x<26;x++ )  // Summing up the counter strings

            {
                s1 += Up[x];
                s2 += Lo[x];
                s3 += Nu[x];
            }
            // Displaying the following statements
            if(s1==0)
                cout<<"\nYour password must contain at least ONE UPPER_CASE letter!!\n";
            if(s2==0)
                cout<<"\nYour password must contain at least ONE LOWER_CASE letter!!\n";
            if(s3==0)
                cout<<"\nYour password must contain at least ONE DIGIT!!\n";

    }// end of first upper if.
    else
    {
        cout<<"\nYou Entered an Invalid Password!!\n";
        cout<<"\nYour password must be at least Six digit!!\n";
    }
    if (!(s1==0 || s2==0 || s3==0)) // to show the password is correct.
        cout<<"\n\nYour Password Is Verified."<<endl; // Entered Password.

return 0;
}