Task: Floyd-Warshall algorithm
C: #include<limits.h>
#include<stdlib.h>
#include<stdio.h>

typedef struct{
    int sourceVertex, destVertex;
    int edgeWeight;
}edge;

typedef struct{
    int vertices, edges;
    edge* edgeMatrix;
}graph;

graph loadGraph(char* fileName){
    FILE* fp = fopen(fileName,"r");
    
    graph G;
    int i;
    
    fscanf(fp,"%d%d",&G.vertices,&G.edges);
    
    G.edgeMatrix = (edge*)malloc(G.edges*sizeof(edge));
    
    for(i=0;i<G.edges;i++)
        fscanf(fp,"%d%d%d",&G.edgeMatrix[i].sourceVertex,&G.edgeMatrix[i].destVertex,&G.edgeMatrix[i].edgeWeight);
    
    fclose(fp);
    
    return G;
}

void floydWarshall(graph g){
    int processWeights[g.vertices][g.vertices], processedVertices[g.vertices][g.vertices];
    int i,j,k;
    
    for(i=0;i<g.vertices;i++)
        for(j=0;j<g.vertices;j++){
            processWeights[i][j] = SHRT_MAX;
            processedVertices[i][j] = (i!=j)?j+1:0;
        }
        
    for(i=0;i<g.edges;i++)
        processWeights[g.edgeMatrix[i].sourceVertex-1][g.edgeMatrix[i].destVertex-1] = g.edgeMatrix[i].edgeWeight;
        
    for(i=0;i<g.vertices;i++)
        for(j=0;j<g.vertices;j++)
            for(k=0;k<g.vertices;k++){
                if(processWeights[j][i] + processWeights[i][k] < processWeights[j][k]){
                    processWeights[j][k] = processWeights[j][i] + processWeights[i][k];
                    processedVertices[j][k] = processedVertices[j][i];
                }
            }
        
    printf("pair    dist   path");
    for(i=0;i<g.vertices;i++)
        for(j=0;j<g.vertices;j++){
            if(i!=j){
                printf("\n%d -> %d %3d %5d",i+1,j+1,processWeights[i][j],i+1);
                k = i+1;
                do{
                    k = processedVertices[k-1][j];
                    printf("->%d",k);
                }while(k!=j+1);
            }
        }
}

int main(int argC,char* argV[]){
    if(argC!=2)
        printf("Usage : %s <file containing graph data>");
    else
        floydWarshall(loadGraph(argV[1]));
    return 0;
}

C#: using System;

namespace FloydWarshallAlgorithm {
    class Program {
        static void FloydWarshall(int[,] weights, int numVerticies) {
            double[,] dist = new double[numVerticies, numVerticies];
            for (int i = 0; i < numVerticies; i++) {
                for (int j = 0; j < numVerticies; j++) {
                    dist[i, j] = double.PositiveInfinity;
                }
            }

            for (int i = 0; i < weights.GetLength(0); i++) {
                dist[weights[i, 0] - 1, weights[i, 1] - 1] = weights[i, 2];
            }

            int[,] next = new int[numVerticies, numVerticies];
            for (int i = 0; i < numVerticies; i++) {
                for (int j = 0; j < numVerticies; j++) {
                    if (i != j) {
                        next[i, j] = j + 1;
                    }
                }
            }

            for (int k = 0; k < numVerticies; k++) {
                for (int i = 0; i < numVerticies; i++) {
                    for (int j = 0; j < numVerticies; j++) {
                        if (dist[i, k] + dist[k, j] < dist[i, j]) {
                            dist[i, j] = dist[i, k] + dist[k, j];
                            next[i, j] = next[i, k];
                        }
                    }
                }
            }

            PrintResult(dist, next);
        }

        static void PrintResult(double[,] dist, int[,] next) {
            Console.WriteLine("pair     dist    path");
            for (int i = 0; i < next.GetLength(0); i++) {
                for (int j = 0; j < next.GetLength(1); j++) {
                    if (i != j) {
                        int u = i + 1;
                        int v = j + 1;
                        string path = string.Format("{0} -> {1}    {2,2:G}     {3}", u, v, dist[i, j], u);
                        do {
                            u = next[u - 1, v - 1];
                            path += " -> " + u;
                        } while (u != v);
                        Console.WriteLine(path);
                    }
                }
            }
        }

        static void Main(string[] args) {
            int[,] weights = { { 1, 3, -2 }, { 2, 1, 4 }, { 2, 3, 3 }, { 3, 4, 2 }, { 4, 2, -1 } };
            int numVerticies = 4;

            FloydWarshall(weights, numVerticies);
        }
    }
}