added disk scheduling diagrams

disk-scheduling/algorithms.typ

@@ -0,0 +1,62 @@
+#let schedule-fcfs(places) = {
+  return places
+}
+
+#let schedule-sstf(places) = {
+  let places = places
+  let cur = places.remove(0)
+  let result = (cur,)
+
+  while places.len() != 0 {
+    let best-d = none
+    let best-i = none
+    for (i, val) in places.enumerate() {
+      let d = calc.abs(cur - val)
+      if best-i == none or d < best-d {
+        best-d = d
+        best-i = i
+      }
+    }
+    cur = places.remove(best-i)
+    result.push(cur)
+  }
+  return result
+}
+
+#let schedule-scan(places, initial-dir, min, max) = {
+  assert(initial-dir in (left, right))
+
+  let first = places.first()
+  let places = places.sorted()
+  let i = places.position(v => v == first)
+  let left-side = places.slice(0, i)
+  let right-side = places.slice(i+1)
+
+  let result = if initial-dir == left {
+    (first,) + left-side.rev() + (min,) + right-side
+  } else {
+    (first,) + right-side + (max,) + left-side.rev()
+  }
+
+  return result
+}
+
+#let schedule-cscan(places, min, max) = {
+  let first = places.first()
+  let places = places.sorted()
+  let i = places.position(v => v == first)
+  let left-side = places.slice(0, i)
+  let right-side = places.slice(i+1)
+
+  return (first,) + right-side + (max, min) + left-side
+}
+
+#let schedule-clook(places) = {
+  let first = places.first()
+  let places = places.sorted()
+  let i = places.position(v => v == first)
+  let left-side = places.slice(0, i)
+  let right-side = places.slice(i+1)
+
+  return (first,) + right-side + left-side
+}