Data update

Task/Dijkstras-algorithm/V-(Vlang)/dijkstras-algorithm.v

@@ -0,0 +1,91 @@
+struct Edge {
+    from string
+    to   string
+    cost int
+}
+
+const   graph := [
+        Edge{"a", "b", 7},
+        Edge{"a", "c", 9},
+        Edge{"a", "f", 14},
+        Edge{"b", "c", 10},
+        Edge{"b", "d", 15},
+        Edge{"c", "d", 11},
+        Edge{"c", "f", 2},
+        Edge{"d", "e", 6},
+        Edge{"e", "f", 9},
+    ]
+
+fn str_to_list(sg string) []string { return sg.split(" ") }
+
+fn powerset(graph []Edge) []string {
+    nir := graph.len
+    max := 1 << nir
+    mut dgraph := []string{}
+    mut sg := ""
+    for ial in 1 .. max {
+        sg = ""
+        for jal in 0 .. nir {
+            if (ial & (1 << jal)) != 0 {
+                edge := graph[jal]
+                sg += "${edge.from} ${edge.to} ${edge.cost} "
+            }
+        }
+        sg = sg.trim_space()
+        dgraph << sg
+    }
+    return dgraph
+}
+
+fn main() {
+    dgraph := powerset(graph)
+    dbegin, dend := "a", "e"
+    mut lenold, mut sumold, mut sumnew := 10, 30, 0
+    mut dtemp, mut gend := [][]string{},  []string{}
+    mut sg := ""
+    mut flag := false
+    for sal in dgraph {
+        dtemp << str_to_list(sal)
+    }
+    for mut path in dtemp {
+        if path.len > 3 && path[0] == dbegin && path[path.len - 2] == dend {
+            flag = true
+            steps := path.len / 3
+            for mal in 0 .. steps - 1 {
+                if mal < steps - 1 {
+                    // check if the "to" of current edge matches "from" of next edge
+                    if path[mal * 3 + 1] != path[(mal + 1) * 3] {
+                        flag = false
+                        break
+                    }
+                }
+            }
+            if flag {
+                lennew := path.len
+                if lennew <= lenold {
+                    lenold = lennew
+                    sumnew = 0
+                    for mal in 0 .. steps {
+                        sumnew += path[mal * 3 + 2].int()
+                    }
+                    if sumnew < sumold {
+                        sumold = sumnew
+                        gend = path.clone()
+                    }
+                }
+            }
+        }
+    }
+    if gend.len == 0 {
+        println("No path found from $dbegin to $dend")
+        return
+    }
+    sg = "$dbegin $dend : "
+    steps := gend.len / 3
+    for mal in 0 .. steps {
+        sg += "${gend[mal * 3]} ${gend[mal * 3 + 1]} ${gend[mal * 3 + 2]} -> "
+    }
+    sg = sg[..sg.len - 4] // remove last arrow character
+    sg += " cost : $sumold\n"
+    print(sg)
+}