Big O day 1

def kangaroo(x1, v1, x2, v2):
    a , b = x1 , x2
    if(v1 <= v2):
        return "NO"
    while a <= b:
        if(a == b):
            return "YES"
        a += v1
        b += v2
    return "NO"

def diagonalDifference(arr):
    a = 0
    b = 0

    for i in range(n):
        a += arr[i][i]
        b += arr[i][n - i - 1]
    return abs(a - b)

def maxMin(m, A):
    A.sort()
    mn = 10**9 + 1
    i , j = 0 , m - 1
    while j < n:
        mn = min(A[j]- A[i] , mn)
        j += 1
        i += 1
    return mn