Revert "Recursion to try a few different routes - score: 47.9M"

This reverts commit 8187c0f1f24c5ee90fee56c8c42a88e404ba6059.

main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"math/rand"
 	"os"
 	"sort"
 )
@@ -135,23 +134,7 @@ func max(a, b int) int {
 	}
 }
 
-var bestTotalScore int
-
-// invariant : when entering and leaving function,
-// Sched has the "same" heap. Same means successive
-// popped values will be the same (but the internal
-// ordering of nodes may be different)
-func Choose(cumulativeScore int, depth int) {
-	if cumulativeScore > bestTotalScore {
-		bestTotalScore = cumulativeScore
-	}
-	c := Sched.Pop()
-	if c == nil {
-		// Stop recursion, empty car list,
-		// could not match cars to rides
-		return
-	}
-
+func Choose(c *Car) *Ride {
 	var bestRides []struct {
 		r         *Ride
 		lenOfRide int
@@ -162,9 +145,9 @@ func Choose(cumulativeScore int, depth int) {
 		if r.used {
 			continue
 		}
-		if r.Length() > 6000 {
-			continue
-		}
+		// if r.Length() > 6000 {
+		// 	continue
+		// }
 		if r.f < c.EarliestFinish(r) {
 			continue
 		}
@@ -180,10 +163,7 @@ func Choose(cumulativeScore int, depth int) {
 			}{r, lenOfRide, total})
 			// shitty sort-of-correct-but-quite-incorrect way
 			// of picking next best n rides
-			n := 1
-			if rand.Intn(max(1, int(N/5))) == 0 {
-				n = 3
-			}
+			n := 3
 			if len(bestRides) > n {
 				bestRides = bestRides[len(bestRides)-n:]
 			}
@@ -193,31 +173,31 @@ func Choose(cumulativeScore int, depth int) {
 	// 	fmt.Printf("Picking %d %d -> %d %d\n", bestRide.a, bestRide.b, bestRide.x, bestRide.y)
 	// }
 	if len(bestRides) != 0 {
-		for _, br := range bestRides {
-			r := br.r
-			r.used = true
-			oldC := *c
-			c.Update(r)
-			Sched.Add(c)
-			// recursion 101
-			Choose(cumulativeScore+c.score-oldC.score, depth+1)
-			Sched.RemoveAtIndex(c.pqindex)
-			// pqindex is meaningless now but it's ok
-			// it will be fixed when c is added again
-			*c = oldC
-			r.used = false
-		}
-	} else {
-		// another car may still have other rides
-		Choose(cumulativeScore, depth)
+		// pick the not quite best ride...hey some
+		// of the inputs already  give a better score !
+		return bestRides[0].r
+		//return bestRides[len(bestRides)-1].r
+	}
+	return nil
+}
+
+func assign() bool {
+	c := Sched.Pop()
+	if c == nil {
+		return false
+	}
+	r := Choose(c)
+	if r == nil {
+		return true
 	}
-	// add back the one we popped at beginning of function
+	r.used = true
+	c.Update(r)
 	Sched.Add(c)
+
+	return true
 }
 
 func solve() {
-	rand.Seed(1)
-
 	sort.Sort(ByEndtime(Rides))
 
 	Sched = &prioq{}
@@ -234,17 +214,19 @@ func solve() {
 		Sched.Add(c)
 	}
 
-	// start recursion
-	Choose(0, 0)
+	for assign() {
+	}
 
+	totalScore := 0
 	for _, c := range Cars {
 		fmt.Fprintf(output, "%d", len(c.Rides))
 		for _, ri := range c.Rides {
 			fmt.Fprintf(output, " %d", ri)
 		}
 		fmt.Fprintf(output, "\n")
+		totalScore += c.score
 	}
-	fmt.Printf("%d\n", bestTotalScore)
+	fmt.Printf("%d\n", totalScore)
 }
 
 func main() {
@@ -340,7 +322,6 @@ func (pq *prioq) RemoveAtIndex(k int) *Car {
 		return elem
 	}
 
-	pq.bintree[k].pqindex = -1
 	elem := pq.bintree[k]
 	// Put last element at hole
 	pq.bintree[k] = pq.bintree[len(pq.bintree)-1]