Data update

Task/Dijkstras-algorithm/EasyLang/dijkstras-algorithm.easy

@@ -0,0 +1,73 @@
+global con[][] n .
+proc read . .
+   repeat
+      s$ = input
+      until s$ = ""
+      a = (strcode substr s$ 1 1) - 96
+      b = (strcode substr s$ 3 1) - 96
+      d = number substr s$ 5 9
+      if a > len con[][]
+         len con[][] a
+      .
+      con[a][] &= b
+      con[a][] &= d
+   .
+   con[][] &= [ ]
+   n = len con[][]
+.
+read
+#
+len cost[] n
+len prev[] n
+#
+proc dijkstra . .
+   for i = 2 to len cost[]
+      cost[i] = 1 / 0
+   .
+   len todo[] n
+   todo[1] = 1
+   repeat
+      min = 1 / 0
+      a = 0
+      for i to len todo[]
+         if todo[i] = 1 and cost[i] < min
+            min = cost[i]
+            a = i
+         .
+      .
+      until a = 0
+      todo[a] = 0
+      for i = 1 step 2 to len con[a][] - 1
+         b = con[a][i]
+         c = con[a][i + 1]
+         if cost[a] + c < cost[b]
+            cost[b] = cost[a] + c
+            prev[b] = a
+            todo[b] = 1
+         .
+      .
+   .
+.
+dijkstra
+#
+func$ gpath nd$ .
+   nd = strcode nd$ - 96
+   while nd <> 1
+      s$ = " -> " & strchar (nd + 96) & s$
+      nd = prev[nd]
+   .
+   return "a" & s$
+.
+print gpath "e"
+print gpath "f"
+#
+input_data
+a b 7
+a c 9
+a f 14
+b c 10
+b d 15
+c d 11
+c f 2
+d e 6
+e f 9