mirror of https://github.com/TheAlgorithms/C
36 lines
919 B
C
36 lines
919 B
C
/**
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* \file
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* \brief [Problem 1](https://projecteuler.net/problem=1) solution
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* \details
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* An Efficient code to print all the sum of all numbers that are multiples of 3
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* & 5 below N.
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*/
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#include <stdio.h>
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/** Main function */
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int main()
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{
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int t;
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printf("Enter number of times you want to try");
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scanf("%d", &t);
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while (t--) // while t > 0, decrement 't' before every iteration
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{
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unsigned long long N, p = 0, sum = 0;
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printf("Enter the value of N ");
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scanf("%lld", &N); // Take input of N from user
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p = (N - 1) / 3;
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sum = ((3 * p * (p + 1)) / 2);
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p = (N - 1) / 5;
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sum = sum + ((5 * p * (p + 1)) / 2);
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p = (N - 1) / 15;
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sum = sum - ((15 * p * (p + 1)) / 2);
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printf("%lld\n", sum); // print the sum of all numbers that are
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// multiples of 3 & 5 below N
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}
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return 0;
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}
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