Prep Kit - Arrays

16 cards·by luc-yahoo

hackerrank

2D sum sections: summary

use nested for loops

2D sum sections: find max of a section

init the max to a known min and increment as new maxes are found

2D sum sections: how many times to loop?

how many sections fit in the array?

left rotation: number of rotations is equiv to

break position

left rotation: how many rotations aka

number to cut from the left

min bribes: how to detect when to exit fast

if the position is too distant from the value

flip and invert a binary array

use two pointers, 1 at each end. invert if the values are the same

Min swaps: define swap func, taking:

whole array, two positions to swap

Min swaps: swap function

set temp to pos1, copy pos2 to pos1, copy temp to pos2

Min swaps: when to call the swap function?

Minimum difference: set res to:

math.inf

Minimum difference: which position to start at?

start at position 1, so we compare each number to the previous

Minimum difference: how to check difference?

diff = min(arr[i+1] - arr[i], res)

Jumping on Clouds: what kind of loop

while loop

Jumping on the Clouds; how to check if close to the end

if pos + 2 > end: increment pos by 1 and jumps by 1

Jumping on the Clouds; how many cases

3; close to the end, a valid long jump, a short jump