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Golang program for implementation of Floyd–Warshall Algorithm

The Floyd–Warshall algorithm compares all possible paths through the graph between each pair of vertices. The problem is to find shortest distances between every pair of vertices in a given edge weighted directed Graph. Here is source code of the Go Program to implement Floyd–Warshall Algorithm.

Example

package main
 
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 finally
    //have the shortest distances between every pair of vertices
    for _, d := range dist {
        fmt.Printf("%4g\n", d)
    }
}

Output

[   0 +Inf +Inf +Inf +Inf +Inf]
[+Inf    0    1   -3    2   -4]
[+Inf    3    0   -4    1   -1]
[+Inf    7    4    0    5    3]
[+Inf    2   -1   -5    0   -2]
[+Inf    8    5    1    6    0]
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