Day 16 screw it

input/16.txt

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+Valve GJ has flow rate=14; tunnels lead to valves UV, AO, MM, UD, GM
+Valve HE has flow rate=0; tunnels lead to valves QE, SV
+Valve ET has flow rate=0; tunnels lead to valves LU, SB
+Valve SG has flow rate=0; tunnels lead to valves FF, SB
+Valve LC has flow rate=0; tunnels lead to valves QJ, GM
+Valve EE has flow rate=13; tunnels lead to valves RE, BR
+Valve AA has flow rate=0; tunnels lead to valves QC, ZR, NT, JG, FO
+Valve TF has flow rate=0; tunnels lead to valves LU, MM
+Valve GO has flow rate=0; tunnels lead to valves LB, AH
+Valve QE has flow rate=24; tunnels lead to valves LG, HE
+Valve MI has flow rate=0; tunnels lead to valves KU, FF
+Valve BR has flow rate=0; tunnels lead to valves HY, EE
+Valve UV has flow rate=0; tunnels lead to valves GP, GJ
+Valve EH has flow rate=0; tunnels lead to valves UU, FF
+Valve WK has flow rate=0; tunnels lead to valves HY, EL
+Valve NT has flow rate=0; tunnels lead to valves FF, AA
+Valve KI has flow rate=0; tunnels lead to valves OQ, AO
+Valve AH has flow rate=22; tunnels lead to valves GO, RE
+Valve EL has flow rate=0; tunnels lead to valves WK, SQ
+Valve GP has flow rate=0; tunnels lead to valves SB, UV
+Valve GM has flow rate=0; tunnels lead to valves LC, GJ
+Valve LU has flow rate=9; tunnels lead to valves UU, DW, TF, ET, ML
+Valve LB has flow rate=0; tunnels lead to valves GO, VI
+Valve QC has flow rate=0; tunnels lead to valves ML, AA
+Valve JJ has flow rate=0; tunnels lead to valves QJ, DV
+Valve MM has flow rate=0; tunnels lead to valves TF, GJ
+Valve VI has flow rate=18; tunnel leads to valve LB
+Valve NV has flow rate=0; tunnels lead to valves SB, KU
+Valve VT has flow rate=0; tunnels lead to valves HY, JG
+Valve RE has flow rate=0; tunnels lead to valves AH, EE
+Valve FO has flow rate=0; tunnels lead to valves SB, AA
+Valve DV has flow rate=10; tunnels lead to valves JH, UD, JJ
+Valve SQ has flow rate=12; tunnels lead to valves EL, QA
+Valve OQ has flow rate=23; tunnels lead to valves KI, IV, JS
+Valve FF has flow rate=3; tunnels lead to valves EU, NT, SG, MI, EH
+Valve IV has flow rate=0; tunnels lead to valves LG, OQ
+Valve HY has flow rate=8; tunnels lead to valves VT, BR, WK
+Valve ML has flow rate=0; tunnels lead to valves LU, QC
+Valve JS has flow rate=0; tunnels lead to valves EM, OQ
+Valve KU has flow rate=5; tunnels lead to valves MI, VL, NV, HU, DW
+Valve QA has flow rate=0; tunnels lead to valves OS, SQ
+Valve EU has flow rate=0; tunnels lead to valves FF, OS
+Valve SV has flow rate=0; tunnels lead to valves QJ, HE
+Valve JG has flow rate=0; tunnels lead to valves AA, VT
+Valve DW has flow rate=0; tunnels lead to valves LU, KU
+Valve UD has flow rate=0; tunnels lead to valves DV, GJ
+Valve QJ has flow rate=17; tunnels lead to valves JJ, SV, LC, EM, YA
+Valve HU has flow rate=0; tunnels lead to valves JH, KU
+Valve ZR has flow rate=0; tunnels lead to valves AA, VL
+Valve YA has flow rate=0; tunnels lead to valves QJ, OS
+Valve JH has flow rate=0; tunnels lead to valves HU, DV
+Valve OS has flow rate=15; tunnels lead to valves EU, YA, QA
+Valve LG has flow rate=0; tunnels lead to valves QE, IV
+Valve SB has flow rate=4; tunnels lead to valves FO, SG, NV, GP, ET
+Valve UU has flow rate=0; tunnels lead to valves EH, LU
+Valve VL has flow rate=0; tunnels lead to valves ZR, KU
+Valve AO has flow rate=0; tunnels lead to valves GJ, KI
+Valve EM has flow rate=0; tunnels lead to valves QJ, JS

src/16.rkt

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+#lang curly-fn racket
+
+(require "../lib.rkt"
+         data/queue
+         (except-in graph transpose))
+
+(define flows (make-hash))
+
+(define graph
+  (for/fold ([edges '()]
+             #:result (unweighted-graph/undirected edges))
+            ([valve (problem-input 16)])
+    (match-let* ([(pregexp "Valve (\\w\\w) has flow rate=(\\d+); tunnels? leads? to valves? (.+)" `(,_ ,v ,r ,ts)) valve]
+                 [valve (string->symbol v)]
+                 [flow (string->number r)])
+      (hash-set! flows valve flow)
+      (for/fold ([edges edges])
+                ([tunnel (string-split ts ", ")])
+        (cons (list valve (string->symbol tunnel)) edges)))))
+
+(define graph*
+  (weighted-graph/undirected
+   (for/list ([(edge weight) (floyd-warshall graph)]
+              #:when (or (and (symbol=? 'AA (first edge))
+                              (not (zero? (hash-ref flows (second edge)))))
+                         (and (not (zero? weight))
+                              (not (zero? (hash-ref flows (first edge))))
+                              (not (zero? (hash-ref flows (second edge)))))))
+     (cons weight edge))))
+
+(define (part1)
+  (define Q (make-queue))
+  (enqueue! Q (list 'AA 30 0 (set 'AA)))
+  (let loop ([pressure 0])
+    (if (queue-empty? Q) pressure
+        (match-let ([`(,v ,t ,p ,seen) (dequeue! Q)])
+          (for ([n (in-neighbors graph* v)]
+                #:when (not (set-member? seen n)))
+            (define time (- t (edge-weight graph* v n) 1))
+            (define flow (hash-ref flows n))
+            (when (> time 0)
+              (enqueue! Q (list n time (+ p (* flow time)) (set-add seen n)))))
+          (loop (max pressure p))))))
+
+(define (part2)
+  (define Q (make-queue))
+  (define paths (make-hash))
+  (enqueue! Q (list 'AA 26 0 (set 'AA)))
+  (let loop ()
+    (if (queue-empty? Q)
+        (for*/max ([(path1 p1) paths]
+                   [(path2 p2) paths]
+                   #:when (set-empty? (set-remove (set-intersect path1 path2) 'AA)))
+          (+ p1 p2))
+        (match-let ([`(,v ,t ,p ,seen) (dequeue! Q)])
+          (for ([n (in-neighbors graph* v)]
+                #:when (not (set-member? seen n)))
+            (define time (- t (edge-weight graph* v n) 1))
+            (define flow (hash-ref flows n))
+            (if (> time 0)
+                (enqueue! Q (list n time (+ p (* flow time)) (set-add seen n)))
+                (hash-set! paths seen (max p (hash-ref paths seen 0)))))
+          (loop)))))
+
+(show-solution* part1 part2)