C programming Math : Exercises, Practice and Solution

C programming Mathematics [28 exercises with solution]

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1. Write a C program to reverse the digits of a given integer. Go to the editor
Example:
Input:
i = 123
i = 208478933
i = -73634
Output:
Reverse integer: 321
Reverse integer: 339874802
Reverse integer: -43637
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2. Write a C program to check whether an integer is a palindrome or not. An integer is a palindrome when it reads the same forward as backward. Go to the editor
Example:
Input:
i = 1221
i = -121
i = 100
Output:
Is Palindrome: 1
Is Palindrome: 0
Is Palindrome: 0
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3. Write a C program to divide two integers (dividend and divisor) without using multiplication, division and mod operator. Go to the editor
Example:
Input:
dividend_num = 7
divisor_num = 2

dividend_num = -17
divisor_num = 5

dividend_num = 35
divisor_num = 7
Output:
Result: 3
Result: -3
Result: 5
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4. Write a C program to calculate x raised to the power n (xⁿ). Go to the editor
Example:
Input:
x = 7.0
n = 2

x = 6.2
n = 3
Output:
Result:(x^n) : 49.000000
Result:(x^n) : 238.328000
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5. The following set contains a total of n! unique permutations
Set: [1, 2, 3, ..., n]
If n =3 we will get the following sequence:
1. "123"
2. "132"
3. "213"
4. "231"
5. "312"
6. "321"
Input: n = 3, k = 4
Output: "231"
Write a C program to get the k^th permutation sequence from two given integers n and k where n is between 1 and 9 inclusive and k is between 1 and n! inclusive. Go to the editor
Example:
Input:
n = 3
int k = 2

n = 4
k = 7
Output:
Kth sequence: 132
Kth sequence: 2134
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6. Write a C program to check if a given string can be interpreted as a decimal number. Go to the editor
Example:
Input:
str_num1[ ] ="1234"
str_num2[ ]=" 0.1 "
str_num3[ ]=" -90e3 "
str_num4[ ]=" 99e2.5 "
Output:
Is the above string is a number? 1
Is the above string is a number? 1
Is the above string is a number? 1
Is the above string is a number? 0
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7. Write a C program to get the fraction part from two given integers representing the numerator and denominator in string format. Go to the editor
Example:
Input:
n = 3
d = 2

n = 4
d = 7
Output:
Fractional part: 1.5
Fractional part: 0.(571428)
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8. Write a C program to get the Excel column title that corresponds to a given column number (integer value). Go to the editor
For example:
1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
...
Example:
Input:
n = 3
n = 27
n = 151
Output:
Excel column title: C
Excel column title: AA
Excel column title: EU
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9. Write a C program to get the column number (integer value) that corresponds to a column title as appear in an Excel sheet. Go to the editor
For example:
A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28
...
Example:
Input:
col_title1[ ] ="C"
col_title2[ ] ="AC"
col_title3[ ] ="ZY"
Output:
Corresponding number: 3
Corresponding number: 29
Corresponding number: 701
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10. Write a C program to find the number of trailing zeroes in a given factorial. Go to the editor
Example 1:
Input: 4
Output: 0
Explanation: 4! = 24, no trailing zero.
Example 2:
Input: 6
Output: 1
Explanation: 6! = 720, one trailing zero.

Example:
Input:
n = 4
n = 5
Output:
Number of trailing zeroes of factorial 4 is 0
Number of trailing zeroes of factorial 5 is 1
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11. Write a C program to count the total number of digit 1 appearing in all positive integers less than or equal to a given integer n. Go to the editor
Example:
Input n = 12,
Return 5, because digit 1 occurred 5 times in the following numbers: 1, 10, 11, 12.
Example:
Input:
n = 12
n = 30
Output:
Total number of digit 1 appearing in 12 (less than or equal) is 5.
Total number of digit 1 appearing in 30 (less than or equal) is 13.
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12. Write a C programming to add repeatedly all digits of a given non-negative number until the result has only one digit. Go to the editor
Example:
Input: 48
Output: 2
Explanation: The formula is like: 4 + 8 = 12, 1 + 2 = 3.
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13. Write a C programming to check if a given integer is a power of three. Go to the editor
Example:
Input: 9
Output: true
Input: 81
Output: true
Input: 45
Output: false
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14. For a non negative integer in the range 0 ≤ i ≤ n write a C programming to calculate the number of 1's in their binary representation and return them as an array. Go to the editor
Example:
Input:
Number: 7
Number of 1's in the binary representation:
0: 0
1: 1
2: 1
3: 2
4: 1
5: 2
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15. Write a C programming to get the maximum product from a given integer after breaking the integer into the sum of at least two positive integers. Go to the editor
Example:
Input: 12
Output: 81
Explanation: 12 = 3 + 3 + 3 + 3, 3 x 3 × 3 × 3 = 81.
Input: 7
Output: 12
Explanation: 7 = 3 + 2 + 2, 3 x 2 x 2 = 12.
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16. Lexicographical order:
From Wikipedia,
In mathematics, the lexicographic or lexicographical order (also known as lexical order, dictionary order, alphabetical order or lexicographic(al) product) is a generalization of the way words are alphabetically ordered based on the alphabetical order of their component letters. This generalization consists primarily in defining a total order on the sequences (often called strings in computer science) of elements of a finite totally ordered set, often called an alphabet.
Write a C programming to print numbers from 1 to an given integer(N) in lexicographic order. Go to the editor
Example:
Input: 10
Output:
Print numbers from 1 to 10 in lexicographic order-
1 10 2 3 4 5 6 7 8 9
Input: 25
Output:
Print numbers from 1 to 25 in lexicographic order-
1 10 11 12 13 14 15 16 17 18 19 2 20 21 22 23 24 25 3 4 5 6 7 8 9
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17. Write a C programming to find the nth digit of number 1 to n?. Go to the editor
Infinite integer sequence: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 .. where n is a positive integer.
Example:
Input:
7
Output:
7
Input:
12
Output:
1
The 12th digit of the sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... is 1, which is part of the number 11.
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18. Write a C programming to find the total number of full staircase rows that can be formed from given number of dices. Go to the editor
Example 1:
n = 5
The dices can form the following rows:

As the 3rd row is incomplete the program will return 2 (full staircase rows).
Example 1:
n = 8 The dices can form the following rows:

As the 4th row is incomplete the program will return 3 (full staircase rows).
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19. Write a C program to find the square root of a number using Babylonian method. Go to the editor
Example 1:
Input: n = 50
Output: 7.071068
Example 2:
Input: n = 17
Output: 4.123106
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20. Write a C program to multiply two integers without using multiplication, division, bitwise operators, and loops. Go to the editor
Example 1:
Input: n1 = 50
Input: n2 = 12
Output: 600
Example 2:
Input: n1 = 0
Input: n2 = 12
Output: 0
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21. Write a C program to calculate and print average (or mean) of the stream of given numbers. Go to the editor
Example 1:
Input:
arr[] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100}
Output:
Average of 1 numbers is 10.000000
Average of 2 numbers is 15.000000
Average of 3 numbers is 20.000000
Average of 4 numbers is 25.000000
Average of 5 numbers is 30.000000
Average of 6 numbers is 35.000000
Average of 7 numbers is 40.000000
Average of 8 numbers is 45.000000
Average of 9 numbers is 50.000000
Average of 10 numbers is 55.000000
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22. Write a C program to count the numbers without digit 7, from 1 to a given number. Go to the editor
Example 1:
Input: n = 10
Output: 9
Example 2:
Input: n = 687
Output: 555
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23. Write a C program to find next smallest palindrome of a given number. Go to the editor
From Wikipedia,
A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam, racecar. There are also numeric palindromes, including date/time stamps using short digits 11/11/11 11:11 and long digits 02/02/2020. Sentence-length palindromes may be written when allowances are made for adjustments to capital letters, punctuation, and word dividers, such as "A man, a plan, a canal, Panama!".
Example 1:
Input: n = 121
Output: Next smallest palindrome of 121 is 131
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24. Write a C program to calculate e raise to the power x using sum of first n terms of Taylor Series. Go to the editor
From Wikipedia,
In mathematics, a Taylor series is a representation of a function as an infinite sum of terms that are calculated from the values of the function's derivatives at a single point.
Example:
The Taylor series for any polynomial is the polynomial itself.

The above expansion holds because the derivative of e^x with respect to x is also e^x, and e⁰ equals 1.
This leaves the terms (x − 0)ⁿ in the numerator and n! in the denominator for each term in the infinite sum.
Example 1:
Input: n = 25
float x= 5.0
Output: e^x = 148.413162
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25. Write a C program to print all prime factors of a given number. Go to the editor
Example 1:
Input: n = 75
Output: All prime factors of 75 are: 3 5 5
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26. Write a C program to check if a given number is Fibonacci number or not. Go to the editor
In mathematics, the Fibonacci numbers, commonly denoted F_n form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is, and for n > 1. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89.
Example 1:
Input: n = 8
Output: 1
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27. Write a C program to multiply two numbers using bitwise operators. Go to the editor

Example 1:
Input: int x = 8
int y = 9
Output: Product of 8 and 9 using bitwise operators is: 72
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28. Write a C program to find angle between given hour and minute hands. Go to the editor

Example 1:
Input: int ha = 11
int ma = 30 Output: Angle between hour and minute hands 165
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