mirror of https://github.com/TheAlgorithms/C
58 lines
1.1 KiB
C
58 lines
1.1 KiB
C
/**
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* @file
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* @brief Strong number is a number whose sum of all digits’ factorial is equal
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* to the number n For example: 145 = 1!(1) + 4!(24) + 5!(120)
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*/
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#include <assert.h>
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#include <stdbool.h>
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#include <stdio.h>
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/**
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* Check if given number is strong number or not
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* @param number
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* @return `true` if given number is strong number, otherwise `false`
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*/
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bool isStrong(int number)
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{
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if (number < 0)
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{
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return false;
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}
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int sum = 0;
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int originalNumber = number;
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while (originalNumber != 0)
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{
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int remainder = originalNumber % 10;
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int factorial = remainder == 0 ? 0 : 1; /* 0! == 1 */
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/* calculate factorial of n */
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for (int i = 1; i <= remainder; factorial *= i, i++)
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{
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;
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}
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sum += factorial;
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originalNumber /= 10;
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}
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return number == sum;
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}
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/**
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* Test function
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* @return void
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*/
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void test()
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{
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assert(isStrong(145)); /* 145 = 1! + 4! + 5! */
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assert(!isStrong(543)); /* 543 != 5!+ 4! + 3! */
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}
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/**
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* Driver Code
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* @return None
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*/
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int main()
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{
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test();
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return 0;
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}
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