具體講解：留個位置，馬上來
Python實現
轉載至CSDN博主chenxing_的《dijkstra算法python實現》，網址：https://blog.csdn.net/chenxing_/article/details/80904016
MAX_value = 999999
def dijkstra(graph, s):
# 判斷圖是否爲空，如果爲空直接退出
if graph is None:
return None
dist = [MAX_value]*len(graph)
dist[s] = 0
S = []
Q = [i for i in range(len(graph))]
dist_init = [i for i in graph[s]]
while Q:
u_dist = min([d for v, d in enumerate(dist_init) if v in Q])
u = dist_init.index(u_dist)
S.append(u)
Q.remove(u)
for v, d in enumerate(graph[u]):
if 0 < d < MAX_value:
if dist[v] > dist[u]+d:
dist[v] = dist[u]+d
dist_init[v] = dist[v]
return dist
if __name__ == '__main__':
graph_list = [ [0, 9, MAX_value, MAX_value, MAX_value, 14,15,MAX_value],
[9, 0, 24, MAX_value, MAX_value, MAX_value,MAX_value,MAX_value],
[MAX_value, 24, 0, 6, 2, 18,MAX_value,19],
[MAX_value, MAX_value, 6, 0, 11,MAX_value,MAX_value, 6],
[MAX_value,MAX_value, 2, 11, 0, 30,20, 16],
[14,MAX_value,18,MAX_value,30,0,5,MAX_value],
[15,MAX_value,MAX_value,MAX_value,20,5,0,44],
[MAX_value,MAX_value,19,6,16,MAX_value,44,0]]
distance = dijkstra(graph_list, 0)
print(distance)
JAVA實現
轉載至CSDN博主charilin的《Dijkstra算法的Java實現》，網址：https://blog.csdn.net/weixin_43806015/article/details/84551023
package suanfa;
public class dijkstra {
public static void main(String[] args) {
char[] vexs = {'A', 'B', 'C', 'D', 'E', 'F', 'G'};
final int INF = Integer.MAX_VALUE;
int matrix[][] = {
/*A*//*B*//*C*//*D*//*E*//*F*//*G*/
/*A*/ { 0, 12, INF, INF, INF, 16, 14},
/*B*/ { 12, 0, 10, INF, INF, 7, INF},
/*C*/ { INF, 10, 0, 3, 5, 6, INF},
/*D*/ { INF, INF, 3, 0, 4, INF, INF},
/*E*/ { INF, INF, 5, 4, 0, 2, 8},
/*F*/ { 16, 7, 6, INF, 2, 0, 9},
/*G*/ { 14, INF, INF, INF, 8, 9, 0}};
matrixUDG mu = new matrixUDG(vexs, matrix);
mu.start(3);
}
}
class matrixUDG {
final int INF = Integer.MAX_VALUE;
int numNodes;
int[][] matrix;
int[] prev ;
int[] dist ;
char[] vexs;
//初始化圖參數
public matrixUDG (char[] vexs, int[][] matrix) {
this.vexs = vexs;
this.matrix = matrix;
numNodes = vexs.length;
prev = new int[numNodes];
dist = new int[numNodes];
}
// 核心代碼！！！！
// 包括三個數組 1.prev（包含當前節點的上一個父類節點） 2.dist（當前節點與原始節點的距離）
// 3.原始矩陣matrix[][],儲存圖 4.isVisited[]標記數組
public void start(int vs) {
//初始化類參數
boolean[] isVisited = new boolean[numNodes ];
for (int i = 0; i < isVisited.length; i++) {
dist[i] = matrix[vs][i];
prev[i] = -1;
if(dist[i] != INF) {
prev[i] = vs;
}
}
isVisited[vs] = true;
//兩次循環
for (int i = 0; i < isVisited.length; i++) {
int min = INF;
int k = 0;
//找到最近的節點
for (int j = 0; j < isVisited.length; j++) {
if(!isVisited[j] && dist[j] < min ) {
min = dist[j];
k = j;
}
}
isVisited[k] = true;
//更新最近路徑和父節點
for (int j = 0; j < isVisited.length; j++) {
if(!isVisited[j] && matrix[k][j] != INF) {
if(dist[j] > matrix[k][j] + dist[k]) {
dist[j] = matrix[k][j] + dist[k] ;
prev[j] = k;
}
}
}
}
//打印節點、路徑、距離
for (int i = 0; i < isVisited.length; i++) {
System.out.print( "節點" + i + " " );
int a = i;
System.out.print("路徑：");
while (a != vs) {
System.out.print( prev[a] +" ");
a = prev[a];
}
System.out.println("距離" + dist[i]);
}
}
}
C++實現
CSDN博主李淡然的《Dijkstra算法（c++版）》，網址：https://blog.csdn.net/qq_39630587/article/details/83240036
#include <iostream>
using namespace std;
void dijkstra();
int e[10][10];
int vis[10];
int dis[10];
int n, m;
int min1 = 99999999;
int u = 0;
int main()
{
cin >> n >> m;
// 初始化鄰接表
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
if (i == j)
{
e[i][j] = 0;
}
else
{
e[i][j] = 99999999;
}
}
}
// 填充數據
for (int i = 1; i <= m; i++)
{
int a, b, c;
cin >> a >> b >> c;
e[a][b] = c;
}
for (int i = 1; i <= n; i++)
{
dis[i] = e[1][i];
}
vis[1] = 1;
dijkstra();
for (int i = 1; i <= n; i++)
{
cout << dis[i];
}
system("pause");
return 0;
}
void dijkstra()
{
for (int i = 1; i <= n - 1; i++)
{
min1 = 99999999;
// 尋找權值最小的點u
for (int j = 1; j <= n; j++)
{
if (vis[j] == 0 && dis[j] < min1)
{
min1 = dis[j];
u = j;
}
}
vis[u] = 1;
for (int v = 1; v <= n; v++)
{
// 對於每個u可達的v來說
if (e[u][v] < 99999999)
{
// 如果當前的dis[v]不滿足三角形不等式，那麼進行鬆弛操作
if (dis[v] > dis[u] + e[u][v])
{
dis[v] = dis[u] + e[u][v];
}
}
}
}
}