88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <math.h>
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#include "io_status.h"
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#include "array.h"
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#include "functions.h"
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double solve6(double, double);
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int main(int argc, char* argv[])
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{
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int task = 6;
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double x, eps;
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double res;
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double diff;
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double t;
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if (!((argc == 3) && sscanf(argv[1], "%le", &x) == 1 && sscanf(argv[2], "%le", &eps) == 1))
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{
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printf("Usage: %s x0 eps\n", argv[0]);
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return 1;
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}
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t = clock();
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res = solve6(x, eps);
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t = (clock() - t) / CLOCKS_PER_SEC;
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diff = fabs(res - cos(x));
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printf ("%s : Task = %d Result = %e Residual = %e Elapsed = %.2f\n", argv[0], task, res, diff, t);
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return 0;
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}
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double solve6(double x, double eps)
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{
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int i = 1, sign = 1, flag = 1;
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double el, res = 0;
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x = fmod(x, 2 * M_PI);
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if (x > M_PI)
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{
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x = x - M_PI;
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sign *= -1;
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}
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if (x < -M_PI)
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{
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x = x + M_PI;
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sign *= -1;
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}
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if (x > M_PI / 2)
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{
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x = M_PI - x;
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sign *= -1;
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}
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if (x < -M_PI / 2)
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{
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x = -M_PI - x;
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sign *= -1;
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}
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if (x > M_PI / 4)
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{
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x = M_PI / 2 - x;
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flag = 0;
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}
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if (x < -M_PI / 4)
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{
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x = -M_PI / 2 - x;
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sign *= -1;
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flag = 0;
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}
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if (flag == 1)
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{
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el = 1;
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while (fabs(el) >= eps)
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{
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res += el;
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el *= -1 * ((x * x) / (4 * i * i - 2 * i));
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i++;
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}
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}
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else
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{
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el = x;
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while (fabs(el) >= eps)
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{
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res += el;
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el *= -1 * ((x * x) / (4 * i * i + 2 * i));
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i++;
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}
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}
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return sign * res;
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}
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