Leetcode 871 Minimum Number of Refueling Stops ||Code + Example + Explanation ||June Daily Challenge

A car travels from a starting position to a destination which is target miles east of the starting position.
Along the way, there are gas stations. Each station[i] represents a gas station that is station[i][0] miles east of the starting position, and has station[i][1] liters of gas.
The car starts with an infinite tank of gas, which initially has startFuel liters of fuel in it. It uses 1 liter of gas per 1 mile that it drives.
When the car reaches a gas station, it may stop and refuel, transferring all the gas from the station into the car.
What is the least number of refueling stops the car must make in order to reach its destination? If it cannot reach the destination, return -1.
Note that if the car reaches a gas station with 0 fuel left, the car can still refuel there. If the car reaches the destination with 0 fuel left, it is still considered to have arrived.
Example 1:
Input: target = 1, startFuel = 1, stations = []
Output: 0
Explanation: We can reach the target without refueling.
Example 2:
Input: target = 100, startFuel = 1, stations = [[10,100]]
Output: -1
Explanation: We can't reach the target (or even the first gas station).
Example 3:
Input: target = 100, startFuel = 10, stations = [[10,60],[20,30],[30,30],[60,40]]
Output: 2
Explanation:
We start with 10 liters of fuel.
We drive to position 10, expending 10 liters of fuel. We refuel from 0 liters to 60 liters of gas.
Then, we drive from position 10 to position 60 (expending 50 liters of fuel),
and refuel from 10 liters to 50 liters of gas. We then drive to and reach the target.
We made 2 refueling stops along the way, so we return 2.
Link to challenge :leetcode.com/problems/minimum...

[@RakeshKumar-ub3nt]

Best explanation among all the available on CZcams for this problem. Great job!

[@ChiragVithlani]

Thank you. Very nicely explained.
We can think of this problem like we need to travel far away and we want to keep minimum number of stops.
Every time fuel station comes we get "spare new empty fuel storage tank" and fill it ( imagine that doesn't count as stop as we are not filling vehicle but "spare new empty fuel storage tank" ).
Now when our vehicle is empty; we get "spare fuel storage tank" with MAX fuel ( and we count how many such storage capacity fuel tank we use till we reach target).

[@p25_rhythm70]

Very good and on point explanation

[@siddharthdwivedi3263]

Clear , concise and nice explanation!! Thank you!!

[@pranavsharma7479]

i did 150-200 problems but still struggle how to solve problems like these, any suggestions/tips for that please

[@amolmishra8621]

Very good explanation. Am glad I came across this channel. Looks like a lot more content to explore as well.
Keep up the good work!

[@i_am_groot3787]

nice explanation and code

[@iamnoob7593]

brilliant alisha , Thank you

[@maddycoder1294]

Just Love your Explanation

[@divyanshuraj4085]

son/daughter for rich businessman xd , btw wonderfull explanation :)

[@anujjain9353]

Thank you for such a simple explanation..

[@darshantripathi9454]

Very Nice example given, I was in same doubt ,that why we are using previously unvisited stations. but now I completely understood👏👏👏

[@dhruvpurwar6642]

Great stuff!!

[@AnshulThk]

Thank you, It was a great explanation

[@anshukumari6226]

Nicely explained !! Thanks Alisha :)

[@sumonchatterjee3340]

loved the explanation.thanks a lot

[@ankoor]

Good explanation!

[@shubhamhire9390]

Such a beautiful explanation, keep up the good work🔥🔥👌👌

[@harshilgandhi2191]

such a beautiful and clear code with proper explanation

[@tryingtomakesenseoftheverse]

best explanation on youtube🙌

[@Kashish_Batra]

great explanation :)

[@reshmamaam1451]

Very good 💯

[@sajalgupta3553]

nice explanation... keep it up :)

[@shubhamsukum]

THanks

[@meershahidmanzoor]

But we have to take a note of our location where we have reached as well as of the location of the filling stations

[@gorakhkumargupta491]

Thank you ma'am

[@sagarbora7768]

ALisha Ur explanation skills are 😍

[@maharajak6578]

best explanation available for this question so far.

[@rbrohitbisht]

Not sure how did you reach point 30 from 60.. it is mentioned, move towards east.. not east to west.. one directional..🤓

[@its_me_hb]

[@shvmsh20]

Uh made it so simple

[@Thescienceworld652]

wow , i have written the exact code like u ... but my code is not running after that i came here .