Data commit

Task/Closest-pair-problem/Icon/closest-pair-problem.icon

@@ -0,0 +1,25 @@
+record point(x,y)
+
+procedure main()
+    minDist := 0
+    minPair := &null
+    every (points := [],p1 := readPoint()) do {
+        if *points == 1 then minDist := dSquared(p1,points[1])
+        every minDist >=:= dSquared(p1,p2 := !points) do minPair := [p1,p2]
+        push(points, p1)
+        }
+
+    if \minPair then {
+        write("(",minPair[1].x,",",minPair[1].y,") -> ",
+              "(",minPair[2].x,",",minPair[2].y,")")
+        }
+    else write("One or fewer points!")
+end
+
+procedure readPoint()  # Skips lines that don't have two numbers on them
+    suspend !&input ? point(numeric(tab(upto(', '))), numeric((move(1),tab(0))))
+end
+
+procedure dSquared(p1,p2)    # Compute the square of the distance
+    return (p2.x-p1.x)^2 + (p2.y-p1.y)^2  # (sufficient for closeness)
+end