86 lines
1.4 KiB
C
86 lines
1.4 KiB
C
#include <stdio.h>
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#include <math.h>
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double piWallis(int n);
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double piGregory(int n);
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double piNilakantha(int n);
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double piEuler(int n);
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void piCompare(double pi);
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int main() {
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int n = 10000;
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double pi;
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pi = piWallis(n);
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piCompare(pi);
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pi = piGregory(n);
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piCompare(pi);
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pi = piNilakantha(n);
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piCompare(pi);
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pi = piEuler(n);
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piCompare(pi);
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}
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double piWallis(int n) {
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int top = 0;
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int bottom = 1;
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double pi = 1;
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for (int i = 0; i < n; i++) {
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top += ((i + 1) % 2) * 2;
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bottom += (i % 2) * 2;
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pi *= (float)top / (float)bottom;
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}
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pi *= 2;
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printf("The %d of pi is: %lf\n",n ,pi);
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return pi;
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}
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double piGregory(int n) {
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int top = 4;
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int bottom = 1;
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double pi = 0;
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for (int i = 0; i < n; i++) {
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bottom = (1 + (2 * i)) * pow(-1, i);
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pi += (float)top / (float)bottom;
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}
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printf("The %d of pi is: %lf\n",n ,pi);
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return pi;
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}
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double piNilakantha(int n) {
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int top = 4;
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int bottom;
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double pi = 3;
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for (int i = 1; i < n; i++) {
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bottom = (2*i) * (2*i+1) * (2*i+2) * pow(-1, i - 1);
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pi += (float)top / (float) bottom;
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}
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printf("The %d of pi is: %lf\n",n ,pi);
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return pi;
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}
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double piEuler(int n) {
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int bottom;
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double pi = 0;
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for (int i = 0; i < n; i++) {
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bottom = pow(i+1,2);
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pi += 1.0 / bottom;
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}
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pi = sqrt(6 * pi);
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printf("The %d of pi is: %lf\n",n ,pi);
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return pi;
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}
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void piCompare(double pi) {
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double diff;
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diff = M_PI - pi;
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printf("%lf\n", diff);
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}
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