Program to check Strength of Password

Difficulty Level : Medium
Last Updated : 02 Feb, 2021

A password is said to be strong if it satisfies the following criteria:

It contains at least one lowercase English character.
It contains at least one uppercase English character.
It contains at least one special character. The special characters are: !@#$%^&*()-+
Its length is at least 8.
It contains at least one digit.

Given a string, find its strength. Let a strong password is one that satisfies all above conditions. A moderate password is one that satisfies first three conditions and has length at least 6. Otherwise password is week.

Examples :

Input : “GeeksforGeeks!@12”
Output : Strong

Input : “gfg!@12”
Output : Moderate

C++

// C++ program to check if a given password is
// strong or not.
#include <bits/stdc++.h>
using namespace std;
 
void printStrongNess(string& input)
{
    int n = input.length();
 
    // Checking lower alphabet in string
    bool hasLower = false, hasUpper = false;
    bool hasDigit = false, specialChar = false;
    string normalChars = "abcdefghijklmnopqrstu"
        "vwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 ";
 
    for (int i = 0; i < n; i++) {
        if (islower(input[i]))
            hasLower = true;
        if (isupper(input[i]))
            hasUpper = true;
        if (isdigit(input[i]))
            hasDigit = true;
 
        size_t special = input.find_first_not_of(normalChars);
        if (special != string::npos)
            specialChar = true;
    }
 
    // Strength of password
    cout << "Strength of password:-";
    if (hasLower && hasUpper && hasDigit && 
        specialChar && (n >= 8))
        cout << "Strong" << endl;
    else if ((hasLower || hasUpper) && 
             specialChar && (n >= 6))
        cout << "Moderate" << endl;
    else
        cout << "Weak" << endl;
}
 
// Driver code
int main()
{
    string input = "GeeksforGeeks!@12";
    printStrongNess(input);
    return 0;
}

Java

// Java implementation fo the above approach
import java.io.*;
import java.util.*;
 
class GFG {
   
   
    public static void printStrongNess(String input)
    {
        // Checking lower alphabet in string
        int n = input.length();
        boolean hasLower = false, hasUpper = false,
                hasDigit = false, specialChar = false;
        Set<Character> set = new HashSet<Character>(
            Arrays.asList('!', '@', '#', '$', '%', '^', '&',
                          '*', '(', ')', '-', '+'));
        for (char i : input.toCharArray())
        {
            if (Character.isLowerCase(i))
                hasLower = true;
            if (Character.isUpperCase(i))
                hasUpper = true;
            if (Character.isDigit(i))
                hasDigit = true;
            if (set.contains(i))
                specialChar = true;
        }
       
        // Strength of password
        System.out.print("Strength of password:- ");
        if (hasDigit && hasLower && hasUpper && specialChar
            && (n >= 8))
            System.out.print(" Strong");
        else if ((hasLower || hasUpper || specialChar)
                 && (n >= 6))
            System.out.print(" Moderate");
        else
            System.out.print(" Weak");
    }
 
    // Driver Code
    public static void main(String[] args)
    {
        String input = "GeeksforGeeks!@12";
        printStrongNess(input);
    }
 
     
}
// contributed by Ashish Chhabra

Python3

# Python3 program to check if a given 
# password is strong or not. 
def printStrongNess(input_string):
     
    n = len(input_string) 
 
    # Checking lower alphabet in string 
    hasLower = False
    hasUpper = False
    hasDigit = False
    specialChar = False
    normalChars = "abcdefghijklmnopqrstu"
    "vwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 "
     
    for i in range(n):
        if input_string[i].islower():
            hasLower = True
        if input_string[i].isupper():
            hasUpper = True
        if input_string[i].isdigit():
            hasDigit = True
        if input_string[i] not in normalChars:
            specialChar = True
 
    # Strength of password 
    print("Strength of password:-", end = "")
    if (hasLower and hasUpper and
        hasDigit and specialChar and n >= 8):
        print("Strong")
         
    elif ((hasLower or hasUpper) and
          specialChar and n >= 6):
        print("Moderate")
    else:
        print("Weak")
 
# Driver code 
if __name__=="__main__": 
     
    input_string = "GeeksforGeeks!@12"
     
    printStrongNess(input_string)
 
# This code is contributed by Yash_R

Output

Strength of password:-Strong

This article is contributed by Apurva Agarwal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
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