Small adjustments.

src/main.rs

@@ -131,15 +131,15 @@ fn series(m: i32, id: i32) -> f64 {
     const EPS : f64 = 1e-17;
 
     let mut ak : f64;
-    let mut s : f64 = 0.0;
     let mut t : f64;
+    let mut s : f64 = 0.0;
 
     for k in 0..id {
       ak = (8 * k + m) as f64;
       t = expm((id - k) as f64, ak);
 
-      s = s + t / ak;
-      s = s - (s as i32) as f64;
+      s += t / ak;
+      s -= (s as i32) as f64;
     }
 
     for k in id..id + 101 {
@@ -150,20 +150,19 @@ fn series(m: i32, id: i32) -> f64 {
           break;
       }
 
-      s = s + t;
-      s = s - (s as i32) as f64;
+      s += t;
+      s -= (s as i32) as f64;
     }
 
     s
 }
 
 fn expm(p: f64, ak: f64) -> f64 {
-    const NTP : usize = 25;
+    if ak == 1.0 {
+        return 0.0;
+    }
 
-    let mut i : i32 = 0;
-    let mut p1 : f64 = p;
-    let mut pt : f64;
-    let mut r : f64 = 1.0;
+    const NTP : usize = 25;
 
     lazy_static! {
         static ref TP : Vec<f64> = {
@@ -177,32 +176,29 @@ fn expm(p: f64, ak: f64) -> f64 {
         };
     }
 
-    if ak == 1.0 {
-        return 0.0;
+    let mut i : usize = 0;
+
+    while TP[i] <= p {
+        i += 1;
     }
 
-    for n in 0..NTP {
-        if TP[n] > p {
-            i = n as i32;
-            break;
-        }
-    }
-
-    pt = TP[(i - 1) as usize];
+    let mut pt = TP[i - 1];
+    let mut p1 : f64 = p;
+    let mut r : f64 = 1.0;
 
     for _ in 1..i + 1 {
       if p1 >= pt {
         r = 16.0 * r;
         r = r - ((r / ak) as i32) as f64 * ak;
 
-        p1 = p1 - pt;
+        p1 -= pt;
       }
 
       pt = 0.5 * pt;
 
       if pt >= 1.0 {
-        r = r * r;
-        r = r - ((r / ak) as i32) as f64 * ak;
+        r *= r;
+        r -= ((r / ak) as i32) as f64 * ak;
       }
     }