Roman to Integer | Leetcode -13 | Algorithms Made Easy

[@AlgorithmsMadeEasy]

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[@nikhiltiwari20]

Please make a series od dsa problem and solution explaination video.

[@ShrutiSingh-l6h]

None of my code run in my leetcode

[@pammcm4542]

Best explanation for this problem on TH-cam. Thanks.

[@stephaniemichelle4604]

wow! I never thought of going reverse. I like your explanation a lot! I was using a switch case with repetitive code.

[@aaqibjavedz2569]

Yeah me neither, I would always start from left -> right and add the numbers.

[@mriduljain1981]

@@aaqibjavedz2569 you could do it in that way too

[@Ziggy0120]

thanks! I have been stuck on this problem for a while now. you made it make a lot of sense!

[@shubhankarmane3172]

This channel provides the best solutions. Keep up the good work.

[@AlgorithmsMadeEasy]

Thanks Shubhankar!!! 🙂

[@SunilSharma-mb2kf]

Just wow. I coded this solution from left to right, but it becomes complicated and lots of conditional statements. Right to left is awesome. Thanks.

[@victorvega2014]

I think it is almost the same.
const s = 'LVIII'
let result = 0
const dict = {
'I': 1,
'V': 5,
'X': 10,
'L': 50,
'C': 100,
'D': 500,
'M': 1000
};
let arr = s.split('');
for (var i = 0; i < arr.length; i++) {
if (dict[arr[i]] < dict[arr[i + 1]]) {
result += (dict[arr[i]]) * (-1)
} else {
result += dict[arr[i]]
}
}
return(result)

[@bostonlights2749]

Good Editing, Clear Voice and clean solution.
I've subscribed

[@AlgorithmsMadeEasy]

Thanks !!

[@alayparikh5622]

Explanation and everything was good. But next time please dont cover up your mistakes. We all are humans (Proof: Check 3rd line of the code at 4:36 and 4:38)

[@ayushsinghrathore360]

Yeh Smart 🤓🤣

[@kunalkheeva]

the perfect explanation and in just 5 minutes!! Thank you.

[@karunasagarks5228]

Really a great video, we need more such Leetcode video solutions! Thank you very much for this one.

[@AlgorithmsMadeEasy]

Glad you enjoyed it!

[@jatinkumar4410]

Your presentation visuals are amazing. Thanks for the content

[@AlgorithmsMadeEasy]

Thank you!!

[@tasneemayham974]

AMAZING CONTENT!!
SIMPLE AND PERFECT!!!!

[@AlgorithmsMadeEasy]

Thank you!!

[@aastikofficial6100]

Very easy and simple approach and well explained crystal clear i used to watch this channel for more videos .Thank you 🌟🌟

[@soumyadipbhowmik2220]

Just watched the video. This is the kind of explanation I was looking for. Subscribed.

[@AlgorithmsMadeEasy]

Glad you enjoyed it!

[@madhukar0721]

we can go forward to it also takes O(n) time complexity
Ping me if u need the code or a Hint

[@maheshjindal2622]

Clean, Crisp, to the point code

[@AlgorithmsMadeEasy]

Appreciate that

[@RohitKumar-tk3df]

The perfect Channel name for the perfect Video. Algorithms made easy.....❤❤❤❤❤

[@-Corvo_Attano]

Better than other explanation videos :) Thank you

[@molyoxide8358]

Thanks for creating this presentation and explanation.

[@AlgorithmsMadeEasy]

Thank you so much!! Do checkout our latest videos too!! 👍👍

[@bikkysharma7253]

right to left approach makes it very easy ,thanks

[@sidharthmalhotra7874]

you made it easier to understand..really great

[@AlgorithmsMadeEasy]

Glad it helped!

[@amanprajapati3417]

you just gave me the new perespective to the question
Thank you

[@fashionbox3072]

it shows error like this :
Line 4: Char 13: error: use of undeclared identifier 'Character'
Map map = new HashMap();

[@rishabhagrawal8938]

Same

[@SubaM-mk9hj]

Perfect explanation mam👏

[@dayakard212]

Mam u kept the solution clean and easy.

[@israelayoade]

Bravo!!! Am clapping.

[@AlgorithmsMadeEasy]

Thanks !!

[@imshivendra]

I don't know why but your code is giving wrong output on geeksforgeeks ide

[@ashishrao1789]

In 3rd line, it is not Map and character C shld be capital ..It is HashMap=new HashMap();

[@vaibhavsharmaqa]

thanks for this!! One query , how can we handle -ve cases like below?
("IV", "IIII") ("IX", "VIIII")
("XL", "XXXX") ("XC", "LXXXX")
("CD", "CCCC") ("CM", "DCCCC")

[@cstechexpert5750]

what if i pass IIX as there is no validation can you please explain

[@justkeepstretching2037]

What's better to use in this case, a hashmap or a switch statement?

[@sudipta_pradhan]

hashmap

[@gautamjh]

@@sudipta_pradhan Why? Arent we using extra space if we use hashmap?

[@julianodesousacervelin143]

@@gautamjh the hashmap doesn't grow, it's constant. It could even be static, therefore, space complexity is still O(1), isn't it?

[@MohammadWasimKhan]

Great explanation. Thankyou so much.😊

[@k23j43]

I have a question, in LeetCode all code should be inside the function? Even the const Map that will be use multiple times? Can I put this map in the Solution class instead?

[@rakshakannu5044]

very well explained!

[@AlgorithmsMadeEasy]

Thanks !

[@codetech-01]

easy to understand explanation. Thank you

[@dharmendraudawat]

nicely explained

[@akami_007]

Thanks a lot mam, this really helped for me !

[@AlgorithmsMadeEasy]

Happy to help!!

[@ShubhamSingh-kx4ov]

great simple and perfect

[@vidhikansara7103]

very nice and easy solution thank you

[@AlgorithmsMadeEasy]

Thanks !!

[@reniside4357]

it is really hard to cope pls how do you guys get so good at understanding stuff like this, how does one even learn programming to understand better.

[@rosonerri-faithful]

Solid Explanation!

[@ManmohanBhardwaj-ft2hu]

Explanation is good 👍but help me for program not working showing this Line 4: Char 13: error: use of undeclared identifier 'character'
Mapmap=new HashMap();

[@vickmaproductions]

Use capital C in the word Character

[@syedhabeebuddin101]

Thanks !

[@sharad3877]

how can we solve it, without using auxillary space?

[@vijaysukumarv3512]

Super explained mam.

[@vigneshbalamurugan6537]

Very useful 🙂

[@AlgorithmsMadeEasy]

Glad you liked it !!

[@poojamaheshwari748]

best explanation

[@shivamswaraj6456]

Thank you so much

[@AlgorithmsMadeEasy]

Happy to help!!

[@imshivendra]

I don't know why but your code is giving wrong output on geeksforgeeks ide. And one more thing why you are taking s.length()-1 why not s.length() ?

[@rohitnegi6463]

Thanks di!!

[@AlgorithmsMadeEasy]

most welcome!!

[@siva.....45]

why we traverse the string from the end???

[@bhuppidhamii]

thank you.....

[@suhaskadu1358]

nice explanation

[@mashapoguajay3322]

mam y we have to perform only friom right to left why nit from startin g index

[@yilinlian7995]

thank you

[@FailReviewYT]

how that mcmxciv come?

[@somsk56]

Is it possible ? without using Map ?

[@arshiyaanjum873]

why should we go from right to left?plzz

[@KAVIBHARATHIP-i5h]

why we are applying a map .why can't put the values in a single line? like (I=1,V=5,C=100,M=1000) LIKE THIS

[@RAUSHANKUMAR-iq4yj]

Thanks❤🌹🙏 a lot😊

[@PrabhatListing]

how can we convert roman numbers into numbers(counting 1,2,3) in word document, I tried but not found solution if u have plz share

[@neerajjatwa2048]

C++ code:
class Solution {
public:
int romanToInt(string s) {
map map;
map['I']=1;
map['V']=5;
map['X']=10;
map['L']=50;
map['C']=100;
map['D']=500;
map['M']=1000;

int result = map[s[s.length()-1]];
for(int i =s.length()-2;i>=0;i--){
if(map[s[i]]

[@vasanthakumars20me3]

Hi mam, i am facing this issue while programming the roman to integer (Syntax Error: invalid syntax
^
Class Solution {
Line 1 (Solution.py))
full program I was did:-
Class Solution {
public int romanToInt(string, s){
Map map = new Hashmap();
map.put("I" , 1);
map.put("V" , 5);
map.put("X" , 10);
map.put("L" , 50);
map.put("C" , 10);
map.put("D" , 500);
map.put("M" , 1000);

int res = map.get(s.charAt(s.length()-1));
for (int i = s.length()-2; i >=0; i--) {
if (map.get(s.chartAt(i)) < map.get (s.charAt(i+1))){
res-=map.get(s.charAt(i));
}
else{
res+=map.get(s.charAt(i));
}
}
return res;
}
}

Do we have a any method to resolve it?

[@ashutoshkabir1657]

Try to use capital c in character not small

[@tcoa11pavanrengade34]

Mapmap = new HashMap();
map.put('I' , 1);
map.put('V' , 5);
map.put('X' , 10);
map.put('L' , 50);
map.put('C' , 100);
map.put('D' , 500);
map.put('M' , 1000);

int res = map.get(s.charAt(s.length()-1));
for (int i = s.length()-2; i >=0; i--) {
if (map.get(s.charAt(i)) < map.get (s.charAt(i+1))){
res-=map.get(s.charAt(i));
}
else{
res+=map.get(s.charAt(i));
}
}
return res;
Use this code, This is edited version of your code.

[@ripplesr5655]

Bro, plz tell me how do I become good at solving these like you? 😭 I Suck more than my life!

[@tasneemayham974]

May anyone please tell me why does my code always ignore the last element?
HashMap map = new HashMap();
map.put('I', 1);
map.put('V', 5);
map.put('X', 10);
map.put('L', 50);
map.put('C', 100);
map.put('D', 500);
map.put('M', 1000);
int total =0;
for(int i=0; i

[@gaurabsingh2760]

Because i does not reaches the last position u should add the corresponding integer value of last character and then your answer will be correct

[@chethan6667k]

is this an easy ques? oh ma god

[@hahadarsh]

I am your 1000th like, haha!

[@AlgorithmsMadeEasy]

Thanks for the like.

[@saiteja335]

awesome

[@ascar66]

Your solution is 5 ms. This solution is 4 ms. Which one is better to choose? public int romanToInt(String s) {
int sum = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == 'I') sum += 1;
if (s.charAt(i) == 'V') sum += 5;
if (s.charAt(i) == 'X') sum += 10;
if (s.charAt(i) == 'L') sum += 50;
if (s.charAt(i) == 'C') sum += 100;
if (s.charAt(i) == 'D') sum += 500;
if (s.charAt(i) == 'M') sum += 1000;
if ( i != 0) {
if (s.charAt(i) == 'V' && s.charAt(i - 1) == 'I') sum -=2;
if (s.charAt(i) == 'X' && s.charAt(i - 1) == 'I') sum -=2;
if (s.charAt(i) == 'L' && s.charAt(i - 1) == 'X') sum -=20;
if (s.charAt(i) == 'C' && s.charAt(i - 1) == 'X') sum -=20;
if (s.charAt(i) == 'D' && s.charAt(i - 1) == 'C') sum -=200;
if (s.charAt(i) == 'M' && s.charAt(i - 1) == 'C') sum -=200;
}
}
return sum;
}

[@CRamPrasannaCV]

Understood :-)

[@shubrochakroborty5918]

just wow

[@shreyamatade409]

C++ code pls

[@yashjain93]

class Solution
{
public:
int romanToInt(string s) {
int ans=0;
mapmp;
mp.insert(make_pair('I',1));
mp.insert(make_pair('V',5));
mp.insert(make_pair('X',10));
mp.insert(make_pair('L',50));
mp.insert(make_pair('C',100));
mp.insert(make_pair('D',500));
mp.insert(make_pair('M',1000));
for(int i=s.length()-2; i>=0;i--){
if(mp[s[i]]

[@nitin4598]

Nice explanation

[@arnabchakraborty246]

Thank you very much