From 1f17712ce4b12e3d2a1b0002f662104ebe196a7e Mon Sep 17 00:00:00 2001
From: ridwanfathin <m.ridwanfathin@gmail.com>
Date: Mon, 12 Oct 2020 09:05:24 +0700
Subject: [PATCH 1/2] add flowd-warshall algorithm

---
 graph/shortest_distance_fw.go | 57 +++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 graph/shortest_distance_fw.go

diff --git a/graph/shortest_distance_fw.go b/graph/shortest_distance_fw.go
new file mode 100644
index 0000000..6bcec67
--- /dev/null
+++ b/graph/shortest_distance_fw.go
@@ -0,0 +1,57 @@
+// shorted distances between every pair of vertices using floyd-warshall algorithm
+// https://en.wikipedia.org/wiki/Floyd%E2%80%93Warshall_algorithm
+// http://www.golangprograms.com/golang-program-for-implementation-of-floyd-warshall-algorithm.html
+package graph
+
+import (
+	"fmt"
+	"math"
+)
+
+type graph struct {
+	to int
+	wt float64
+}
+
+func floydWarshall(g [][]graph) [][]float64 {
+	dist := make([][]float64, len(g))
+	for i := range dist {
+		di := make([]float64, len(g))
+		for j := range di {
+			di[j] = math.Inf(1)
+		}
+		di[i] = 0
+		dist[i] = di
+	}
+	for u, graphs := range g {
+		for _, v := range graphs {
+			dist[u][v.to] = v.wt
+		}
+	}
+	for k, dk := range dist {
+		for _, di := range dist {
+			for j, dij := range di {
+				if d := di[k] + dk[j]; dij > d {
+					di[j] = d
+				}
+			}
+		}
+	}
+	return dist
+}
+
+func main() {
+	gra := [][]graph{
+		1: {{2, 3}, {3, 8}, {5, -4}},
+		2: {{4, 1}, {5, 7}},
+		3: {{2, 4}},
+		4: {{1, 2}, {3, -5}},
+		5: {{4, 6}},
+	}
+
+	dist := floydWarshall(gra)
+	//dist[][] will be the output matrix that will have the shortest distances between every pair of vertices
+	for _, d := range dist {
+		fmt.Printf("%4g\n", d)
+	}
+}

From 13b2e9dab7f1c78d4006a7b4010bed47731528c5 Mon Sep 17 00:00:00 2001
From: ridwanfathin <m.ridwanfathin@gmail.com>
Date: Mon, 12 Oct 2020 09:06:33 +0700
Subject: [PATCH 2/2] fix comment typo

---
 graph/shortest_distance_fw.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/graph/shortest_distance_fw.go b/graph/shortest_distance_fw.go
index 6bcec67..f66cd12 100644
--- a/graph/shortest_distance_fw.go
+++ b/graph/shortest_distance_fw.go
@@ -1,4 +1,4 @@
-// shorted distances between every pair of vertices using floyd-warshall algorithm
+// shortest distances between every pair of vertices using floyd-warshall algorithm
 // https://en.wikipedia.org/wiki/Floyd%E2%80%93Warshall_algorithm
 // http://www.golangprograms.com/golang-program-for-implementation-of-floyd-warshall-algorithm.html
 package graph