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DL6ER
51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
/* Pi-hole: A black hole for Internet advertisements
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* (c) 2019 Pi-hole, LLC (https://pi-hole.net)
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* Network-wide ad blocking via your own hardware.
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*
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* FTL Engine
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* Math Implementation
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*
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* This file is copyright under the latest version of the EUPL.
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* Please see LICENSE file for your rights under this license. */
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#include "math.h"
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// Recursive function that returns square root
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__attribute__((const)) double Square(const double n, const double i, const double j)
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{
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double mid = (i + j) / 2;
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double mul = mid * mid;
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if ((mul - n)*(mul - n) < (SQRT_PRECISION * SQRT_PRECISION))
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{
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return mid;
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}
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else if (mul < n)
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{
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return Square(n, mid, j);
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}
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else
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{
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return Square(n, i, mid);
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}
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}
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// Function to find the square root of n
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__attribute__((const)) double my_sqrt(const double n)
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{
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// While the square root is not found
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for(double i = 1.0; true; i++)
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{
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if ((i - n)*(i - n) < (SQRT_PRECISION * SQRT_PRECISION))
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{
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// If n is a perfect square
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return i;
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}
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else if (i * i > n)
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{
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// Square root is in [i-1, i]
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return Square(n, i - 1, i);
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}
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i++;
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}
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}
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