add approximation of pi

This commit is contained in:
neingeist 2013-05-09 19:18:10 +02:00
commit 6298288d58
2 changed files with 26 additions and 0 deletions

3
Makefile Normal file
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CFLAGS=-std=c99
all: approximate-pi

23
approximate-pi.c Normal file
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#include <stdio.h>
#include <stdbool.h>
double approximate_pi(unsigned int steps) {
double approximate_pi = 4.0;
bool subtract = true;
for(int i=2; i<=steps; i++) {
if (subtract) {
approximate_pi -= (4.0/(i*2-1));
} else {
approximate_pi += (4.0/(i*2-1));
}
subtract = !subtract;
}
return approximate_pi;
}
int main(int argc, char *argv[]) {
// printf("sizeof(int) = %d\n", sizeof(int));
printf("pi = %8.7f\n", approximate_pi(10000000));
}