This Apple Coding Question is Awesome! | Leetcode 3019 - Number of Changing Keys

FAANG Coding Interviews / Data Structures and Algorithms / Leetcode

[GregHogg]

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[dvillegas]

Brother you didn’t update the last_used in your code

[nyantheburrito]

huh? this was extremely easy. I've never been in an interview, but i feel like they would never ask such question

[brandonsager]

def chngs(s):
s=s.lower()
changes = 0
for i in range(len(s)-1):
if s[i] != s[i+1]:
changes = changes + 1
else:
pass
return changes

[hola-hola-]

Or simple define a function that checks if two input chars are the same or not. And then apply this func to each pair of adjacent characters. On every true, update the anser by one. Code

ans = 0

for i in range(1, len(str)):
ans += isDiff(str[i], str[I - 1])

[shristisrivastava]

Thank you for making these shorts .They are amazing

[InfernalJoy]

You gotta start adding medium or hard questions

[NumeroTredeci]

You don't need to duplicate lower(), you use lower() in if statements so on the var last_used = s[0] you don't need lower()

[sprajosh]

It’s way easier to lower the string, loop over it with a pointer and compare s[i] with s[i+1]

[TheMachina]

for the ignore casing you can just do if ((letter | 32) == (last_letter | 32)

[subrata.._]

void main() {
String a = 'abBbaa';
String countCh = 'a';
int count = 0;
for (int i = 0; i < a.length; i++) {
if (a[i] == countCh) {
count++;
}
}
print(count);
}

[davidbass]

for(int i=0, j=1; j<arr.length;i++, j++)
if(arr[i]!=arr[j]) count++;

[phyyl]

Here's mine in C#:
int CountChanges(string str)
{
int count = 0;
char lastChar = (char)(str[0] | 0b0010_0000);

for (int i = 1; i < str.Length; i++)
{
char current = (char)(str[i] | 0b0010_0000);
if (lastChar != current)
{
count++;
}
lastChar = current;
}

return count;
}

[ivanshelonik]

class Solution:
def countKeyChanges(self, s: str) -> int:
counter = 0
for i in range(1, len(s)):
curr = s[i]
prev = s[i-1]
if curr.lower() != prev.lower():
counter +=1
return counter

[RenderFaze]

I’ve been coding for a year and I solved this in the time you took to explain it

[anhkhoiaoduy]

When you know the question is asked in easy mode! None other chances of Hard or Moderate Questions be asked in interview shall become trivial and normacy without a doubt.

[mrdiamond]

Why not lowercase the entire string at the start of the function?

[debanganroy]

Bro can you share a link along with this videos so people can practice afterwards

[MyCodingDiary]

You have such a knack for explaining things clearly. Awesome job!

[SR-tijj]

GOAT implementation:
fn = lambda s: sum(1 for i in range(1, len(s)) if abs(ord(s[i]) - ord(s[i - 1])) not in [0, 32])