Merge pull request kelvins#116 from alelimasilva/main

Adicionando Floyd-Warshall

Author: kelvins

README.md

@@ -7,7 +7,7 @@ Com o objetivo de alcançar uma abrangência maior e encorajar novas pessoas a c
 | Algoritmos                      | C                                       | C++                                       | Java                                           | Python                                               | Go                                                  | Ruby                                           | JS                                                | Pascal                                     | Swift                                        | Rust                                           |
 | ------------------------------- | --------------------------------------- | ----------------------------------------- | ---------------------------------------------- | ---------------------------------------------------- | --------------------------------------------------- | ---------------------------------------------- | ------------------------------------------------- | ------------------------------------------ | -------------------------------------------- | ---------------------------------------------- |
 | [Algoritmo Dijkstra][1]         | [C](./src/c/AlgoritmoDijkstra.c)        | C++                                       | [Java](./src/java/Dijkstra.java)               | [Python](./src/python/dijkstra.py)                   | [Go](./src/go/dijkstra/dijkstra.go)                 | Ruby                                           | [JS](src/javascript/AlgoritmoDijkstra.js)         | Pascal                                     | Swift                                        | Rust                                           |
-| [Algoritmo Floyd Warshall][2]   | [C](./src/c/AlgoritmoFloydWarshall.c)   | C++                                       | Java                                           | Python                                               | Go                                                  | Ruby                                           | JS                                                | Pascal                                     | Swift                                        | Rust                                           |
+| [Algoritmo Floyd Warshall][2]   | [C](./src/c/AlgoritmoFloydWarshall.c)   | C++                                       | Java                                           | [Python](./src/python/floyd-warshall.py)                                               | Go                                                  | Ruby                                           | JS                                                | Pascal                                     | Swift                                        | Rust                                           |
 | [Busca Binária][5]              | C                                       | [C++](./src/cpp/BinarySearch.cpp)         | Java                                           | [Python](./src/python/busca_binaria.py)              | [Go](./src/go/busca_binaria/busca_binaria.go)       | [Ruby](./src/ruby/BuscaBinaria.rb)             | [JS](./src/javascript/BinarySearch.js)            | [Pascal](./src/pascal/busca-binaria.pas)   | Swift                                        | Rust                                           |
 | [Busca em Grafos][6]            | [C](./src/c/BuscaEmGrafo.c)             | C++                                       | Java                                           | [Python](./src/python/busca_em_grafo.py)             | Go                                                  | Ruby                                           | [JS](./src/javascript/GraphSearch.js)             | Pascal                                     | Swift                                        | Rust                                           |
 | [Busca Sequencial][7]           | [C](./src/c/BuscaSequencial.c)          | C++                                       | Java                                           | [Python](./src/python/busca_sequencial.py)           | Go                                                  | [Ruby](./src/ruby/BuscaSequencial.rb)          | [JS](./src/javascript/BuscaLinear.js)             | Pascal                                     | Swift                                        | Rust                                           |

src/python/floyd-warshall.py

@@ -0,0 +1,50 @@
+# Grafos - Algoritmo de Floyd-Warshall em Python
+# Alexandre Lima - 2021
+# https://github.com/alelimasilva
+
+from math import inf
+
+def gerar_matriz (n_linhas, n_colunas):
+    return [[0]*n_colunas for _ in range(n_linhas)]
+
+def imprime(matriz, vertices):
+    print(' ', end='')
+    for i in range(vertices):
+        print("  ",i + 1,end='')
+    print('')
+    for i in range(vertices):
+        print(i + 1, matriz[i])
+
+def floyd_warshall(matriz, vertices):
+    dist = gerar_matriz(vertices, vertices)
+    # inicializando a matriz com infinito nas diagonais e as distancias das arestas
+    for i in range(vertices):
+        for j in range(vertices):
+            if(i != j):
+                if(matriz[i][j] != 0):
+                    dist[i][j] = matriz[i][j]
+                else:
+                    dist[i][j] = inf
+            else:
+                dist[i][i] = inf
+    # Floyd-Warshal
+    for k in range(vertices):
+        for i in range(vertices):
+            for j in range(vertices):
+                Dist = inf
+                if(dist[i][k] != inf or dist[k][j] != inf):
+                    Dist = dist[i][k] + dist[k][j]
+ 
+                if(i != j and Dist != inf and Dist < dist[i][j]):
+                    dist[i][j] = Dist
+    # printando o resultado
+    print('Matriz de distâncias')
+    imprime(dist, vertices)
+
+def main():
+    grafo = [[0,3,4,0],[0,0,0,5],[0,0,0,3],[8,0,0,0]]
+    vertices = 4
+    floyd_warshall(grafo, vertices)
+
+if __name__ == "__main__" :
+    main()