## Description

A password is considered strong if the below conditions are all met:

• It has at least 6 characters and at most 20 characters.
• It contains at least one lowercase letter, at least one uppercase letter, and at least one digit.
• It does not contain three repeating characters in a row (i.e., "Baaabb0" is weak, but "Baaba0" is strong).

Given a string password, return the minimum number of steps required to make password strong. if password is already strong, return 0.

In one step, you can:

• Insert one character to password,
• Delete one character from password, or
• Replace one character of password with another character.

Example 1:

Input: password = "a"
Output: 5


Example 2:

Input: password = "aA1"
Output: 3


Example 3:

Input: password = "1337C0d3"
Output: 0


Constraints:

• 1 <= password.length <= 50
• password consists of letters, digits, dot '.' or exclamation mark '!'.

## Solutions

• class Solution {
if (n < 6) {
return Math.max(6 - n, 3 - types);
}
if (n <= 20) {
int replace = 0;
int cnt = 0;
char prev = '~';
for (char curr : chars) {
if (curr == prev) {
++cnt;
} else {
replace += cnt / 3;
cnt = 1;
prev = curr;
}
}
replace += cnt / 3;
return Math.max(replace, 3 - types);
}
int replace = 0, remove = n - 20;
int remove2 = 0;
int cnt = 0;
char prev = '~';
for (char curr : chars) {
if (curr == prev) {
++cnt;
} else {
if (remove > 0 && cnt >= 3) {
if (cnt % 3 == 0) {
--remove;
--replace;
} else if (cnt % 3 == 1) {
++remove2;
}
}
replace += cnt / 3;
cnt = 1;
prev = curr;
}
}
if (remove > 0 && cnt >= 3) {
if (cnt % 3 == 0) {
--remove;
--replace;
} else if (cnt % 3 == 1) {
++remove2;
}
}
replace += cnt / 3;

int use2 = Math.min(Math.min(replace, remove2), remove / 2);
replace -= use2;
remove -= use2 * 2;

int use3 = Math.min(replace, remove / 3);
replace -= use3;
remove -= use3 * 3;
return (n - 20) + Math.max(replace, 3 - types);
}

private int countTypes(String s) {
int a = 0, b = 0, c = 0;
for (char ch : s.toCharArray()) {
if (Character.isLowerCase(ch)) {
a = 1;
} else if (Character.isUpperCase(ch)) {
b = 1;
} else if (Character.isDigit(ch)) {
c = 1;
}
}
return a + b + c;
}
}

• class Solution {
public:
if (n < 6) return max(6 - n, 3 - types);
if (n <= 20) {
int replace = 0, cnt = 0;
char prev = '~';
for (char& curr : password) {
if (curr == prev)
++cnt;
else {
replace += cnt / 3;
cnt = 1;
prev = curr;
}
}
replace += cnt / 3;
return max(replace, 3 - types);
}
int replace = 0, remove = n - 20;
int remove2 = 0;
int cnt = 0;
char prev = '~';
for (char& curr : password) {
if (curr == prev)
++cnt;
else {
if (remove > 0 && cnt >= 3) {
if (cnt % 3 == 0) {
--remove;
--replace;
} else if (cnt % 3 == 1)
++remove2;
}
replace += cnt / 3;
cnt = 1;
prev = curr;
}
}
if (remove > 0 && cnt >= 3) {
if (cnt % 3 == 0) {
--remove;
--replace;
} else if (cnt % 3 == 1)
++remove2;
}
replace += cnt / 3;

int use2 = min(min(replace, remove2), remove / 2);
replace -= use2;
remove -= use2 * 2;

int use3 = min(replace, remove / 3);
replace -= use3;
remove -= use3 * 3;
return (n - 20) + max(replace, 3 - types);
}

int countTypes(string& s) {
int a = 0, b = 0, c = 0;
for (char& ch : s) {
if (islower(ch))
a = 1;
else if (isupper(ch))
b = 1;
else if (isdigit(ch))
c = 1;
}
return a + b + c;
}
};

• class Solution:
def countTypes(s):
a = b = c = 0
for ch in s:
if ch.islower():
a = 1
elif ch.isupper():
b = 1
elif ch.isdigit():
c = 1
return a + b + c

if n < 6:
return max(6 - n, 3 - types)
if n <= 20:
replace = cnt = 0
prev = '~'
if curr == prev:
cnt += 1
else:
replace += cnt // 3
cnt = 1
prev = curr
replace += cnt // 3
return max(replace, 3 - types)
replace = cnt = 0
remove, remove2 = n - 20, 0
prev = '~'
if curr == prev:
cnt += 1
else:
if remove > 0 and cnt >= 3:
if cnt % 3 == 0:
remove -= 1
replace -= 1
elif cnt % 3 == 1:
remove2 += 1
replace += cnt // 3
cnt = 1
prev = curr
if remove > 0 and cnt >= 3:
if cnt % 3 == 0:
remove -= 1
replace -= 1
elif cnt % 3 == 1:
remove2 += 1
replace += cnt // 3
use2 = min(replace, remove2, remove // 2)
replace -= use2
remove -= use2 * 2

use3 = min(replace, remove // 3)
replace -= use3
remove -= use3 * 3
return n - 20 + max(replace, 3 - types)