These are my solutions to HackerRank problem solving exercises:

    Diagonal Difference

                                        
                                            def diagonalDifference(arr):
                                            dp = 0
                                            ds = 0
                                            n = len(arr) - 1
                                            for i in range(0, len(arr)):
                                                    dp += arr[i][i]
                                                    ds += arr[i][n - i]
                                            difference = abs(dp - ds)
                                            return difference
                                        
                                    
    Plus Minus
                                        
                                            def plusMinus(arr):
                                            cntPoz = 0
                                            cntNeg = 0
                                            cntZero = 0
                                            for x in arr:
                                                if x < 0:
                                                    cntNeg += 1;
                                                elif x == 0 : 
                                                    cntZero += 1;
                                                else:
                                                    cntPoz += 1
                                            print(round(cntPoz / len(arr), 6))
                                            print(round(cntNeg / len(arr), 6))
                                            print(round(cntZero / len(arr),6))
                                        
                                    
    Staircase
                                        
                                            def staircase(n):
                                            for i in range(0, n):
                                                line = ''
                                                for j in range(0, n):
                                                    if i + j < (n - 1):
                                                        line += ' '
                                                    else:
                                                        line += '#'
                                                print(line)
                                        
                                    
    Mini-Max Sum
                                        
                                            def miniMaxSum(arr):
                                                minimum = float('inf')
                                                maximum = float('-inf')
                                                sumArr = 0
    
                                                for x in arr:
                                                    if minimum > x:
                                                        minimum = x
                                                    if maximum < x:
                                                        maximum = x
                                                    sumArr += x;
                                                print(sumArr - maximum, sumArr - minimum)
                                        
                                    
    Birthday Cake Candles
                                        
                                            def birthdayCakeCandles(candles):
                                            maximum = float('-inf');
                                            cntMaximum = 0
                                            for x in candles:
                                                if maximum < x:
                                                    maximum = x;
                                            for x in candles:
                                                if x == maximum:
                                                    cntMaximum += 1
                                            return cntMaximum;
                                        
                                    
    Time Conversion
                                        
                                            def timeConversion(s):
                                                h = int(s[:2]);
                                                res = ''
                                                if s[8] == 'A':
                                                    if h == 12:
                                                        res += '0';
                                                        res += '0';
                                                    else:
                                                        res += s[0]
                                                        res += s[1]
                                                    for i in range(2, 8):
                                                        res += s[i]
                                                else:
                                                    if h != 12:
                                                        h += 12;
                                                        res += chr(int(h / 10) % 10 + ord('0'))
                                                        res += chr(int(h % 10) + ord('0'))
                                                    else:
                                                        res += s[0]
                                                        res += s[1]
                                                    for i in range(2, 8):
                                                        res += s[i]
                                                return res
                                        
                                    
    Grading Students
                                        
                                            def gradingStudents(grades):
                                                for i in range(0, len(grades)):
                                                    grade = grades[i]
                                                    if grade >= 38:
                                                        u = grade % 10;
                                                        z = (grade / 10) % 10;
                                                        if u == 4 or u == 3:
                                                            grade = (grade // 10) * 10 + 5;
                                                        if u == 9 or u == 8:
                                                            grade = (grade // 10 + 1) * 10;
                                                    grades[i] = grade;
                                                    
                                                return grades;
                                        
                                    
    Apple and Orange
                                        
                                            def countApplesAndOranges(s, t, a, b, apples, oranges):
                                                cnt_apples = 0
                                                cnt_oranges = 0
                                                for apple in apples:
                                                    dist = apple + a;
                                                    if dist >= s and dist <= t:
                                                        cnt_apples += 1
                                                for orange in oranges:
                                                    dist = orange + b;
                                                    if dist >= s and dist <= t:
                                                        cnt_oranges += 1
                                                print(cnt_apples)
                                                print(cnt_oranges)
                                        
                                    
    Number Line Jumps
                                        
                                            def kangaroo(x1, v1, x2, v2):
                                            while x1 != x2:
                                                if (x1 > x2 and v1 > v2) or (x1 < x2 and v1 < v2):
                                                    return 'NO';
                                                x1 += v1;
                                                x2 += v2
                                            return "YES"                                    
                                        
                                    
    Between Two Sets
                                        
                                            def getTotalX(a, b):
                                                res = 0
                                                
                                                for i in range (1, 101):
                                                    isFactor = True
                                                    for x in b:
                                                        if x % i != 0:
                                                            isFactor = False;
                                                    if isFactor:
                                                        for x in a:
                                                            if i % x != 0:
                                                                isFactor = False;
                                                        if isFactor == True:
                                                            res += 1
                                                return res;                                   
                                        
                                    
    Breaking the Records
                                        
                                            def breakingRecords(scores):
                                                minimum = maximum = scores[0]
                                                cntMin = 0
                                                cntMax = 0
                                                for x in scores:
                                                    if maximum < x:
                                                        maximum = x;
                                                        cntMax += 1;
                                                    if minimum > x:
                                                        minimum = x;
                                                        cntMin += 1;
                                                return [cntMax, cntMin];  
                                        
                                    
    Subarray Division
                                        
                                            def birthday(s, d, m):
                                                cnt = 0
                                                c_sum = 0
                                                i = 0
                                                j = (i + m - 1)
                                                for x in range(i, j + 1):
                                                    c_sum += s[x]
    
                                                while j < len(s):
                                                    if c_sum == d:
                                                        cnt += 1
                                                    c_sum -= s[i]
                                                    i += 1
                                                    j += 1
                                                    if j < len(s):
                                                        c_sum += s[j]
                                                return cnt
                                        
                                    
    Extra Long Factorials
                                        
                                            def extraLongFactorials(n):
                                                bigFactorial = 1
                                                while n >= 2:
                                                    bigFactorial *= n
                                                    n -= 1
                                                print(bigFactorial)
                                        
                                    
    Non-Divisible Subset
                                        
                                            def nonDivisibleSubset(k, s):        
                                                reminder = [0] * k
                                                for i in s:
                                                    reminder[i % k] += 1
                                                maxnum = 0
                                                maxnum += min(reminder[0], 1)
                                                if k % 2 == 0:
                                                    maxnum += min(reminder[k // 2], 1)
                                                for i in range(1, k // 2 + 1):
                                                    if i != k - i:
                                                        maxnum += max(reminder[i], reminder[k - i])
                                                return maxnum
                                        
                                    
    Divisible Sum Pairs
                                        
                                            def divisibleSumPairs(n, k, ar):
                                                cnt = 0
                                                for i in range(0, n - 1):
                                                    for j in range(i + 1, n):
                                                        if (ar[i] + ar[j]) % k == 0:
                                                            cnt += 1
                                                return cnt