Data commit

Task/Pi/Rust/pi.rust

@@ -0,0 +1,37 @@
+use num_bigint::BigInt;
+
+fn main() {
+    calc_pi();
+}
+
+fn calc_pi() {
+    let mut q = BigInt::from(1);
+    let mut r = BigInt::from(0);
+    let mut t = BigInt::from(1);
+    let mut k = BigInt::from(1);
+    let mut n = BigInt::from(3);
+    let mut l = BigInt::from(3);
+    let mut first = true;
+    loop {
+        if &q * 4 + &r - &t < &n * &t {
+            print!("{}", n);
+            if first {
+                print!(".");
+                first = false;
+            }
+            let nr = (&r - &n * &t) * 10;
+            n = (&q * 3 + &r) * 10 / &t - &n * 10;
+            q *= 10;
+            r = nr;
+        } else {
+            let nr = (&q * 2 + &r) * &l;
+            let nn = (&q * &k * 7 + 2 + &r * &l) / (&t * &l);
+            q *= &k;
+            t *= &l;
+            l += 2;
+            k += 1;
+            n = nn;
+            r = nr;
+        }
+    }
+}