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c: Dijkstra's Algorithm

发布时间 2023-09-26 17:11:18作者: ®Geovin Du Dream Park™

 

DijkstrasAlgorithm.h
 
/**
 * *****************************************************************************
 * @file        DijkstrasAlgorithm.h
 * @brief       Dijkstra's Algorithm in C 迪杰斯特拉算法 最短路径算法 https://www.programiz.com/dsa/dijkstra-algorithm#google_vignette
 * IDE: VSCODE C11
 * @author       (geovindu,Geovin Du,涂聚文)
 * @date        2023-09-26
 * @copyright   geovindu
 * *****************************************************************************
 */

#ifndef DIJKSTRASALGORITHM_H
#define DIJKSTRASALGORITHM_H

#include <stdio.h>

#define INFINITY 9999
#define MAX 10

/**
 * @brief     Dijkstra's Algorithm  
 * 
 * @param       Graph 
 * @param       n 
 * @param       start 
 */
void Dijkstra(int Graph[MAX][MAX], int n, int start);


#endif

　　

DijkstrasAlgorithm.c
 
/**
 * *****************************************************************************
 * @file        DijkstrasAlgorithm.c
 * @brief    Dijkstra's Algorithm in C 迪杰斯特拉算法 最短路径算法
 * IDE: VSCODE C11    https://www.programiz.com/dsa/dijkstra-algorithm#google_vignette
 * @author       (geovindu,Geovin Du,涂聚文)
 * @date        2023-09-26
 * @copyright   geovindu
 * *****************************************************************************
 */

#include <stdio.h>
#include "include/DijkstrasAlgorithm.h"



/**
 * @brief       
 * 
 * @param       Graph 
 * @param       n 
 * @param       start 
 */
void Dijkstra(int Graph[MAX][MAX], int n, int start) {
  int cost[MAX][MAX], distance[MAX], pred[MAX];
  int visited[MAX], count, mindistance, nextnode, i, j;

  // Creating cost matrix
  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
      if (Graph[i][j] == 0)
        cost[i][j] = INFINITY;
      else
        cost[i][j] = Graph[i][j];

  for (i = 0; i < n; i++) {
    distance[i] = cost[start][i];
    pred[i] = start;
    visited[i] = 0;
  }

  distance[start] = 0;
  visited[start] = 1;
  count = 1;

  while (count < n - 1) {
    mindistance = INFINITY;

    for (i = 0; i < n; i++)
      if (distance[i] < mindistance && !visited[i]) {
        mindistance = distance[i];
        nextnode = i;
      }

    visited[nextnode] = 1;
    for (i = 0; i < n; i++)
      if (!visited[i])
        if (mindistance + cost[nextnode][i] < distance[i]) {
          distance[i] = mindistance + cost[nextnode][i];
          pred[i] = nextnode;
        }
    count++;
  }

  // Printing the distance
  for (i = 0; i < n; i++)
    if (i != start) {
      printf("\nDijkstra's Algorithm Distance from source to %d: %d", i, distance[i]);
    }
}

　　

调用：

   //15 Dijkstra's Algorithm 迪杰斯特拉算法 最短路径算法
    int Graph[MAX][MAX], j, u;
    n = 7;

    Graph[0][0] = 0;
    Graph[0][1] = 0;
    Graph[0][2] = 1;
    Graph[0][3] = 2;
    Graph[0][4] = 0;
    Graph[0][5] = 0;
    Graph[0][6] = 0;

    Graph[1][0] = 0;
    Graph[1][1] = 0;
    Graph[1][2] = 2;
    Graph[1][3] = 0;
    Graph[1][4] = 0;
    Graph[1][5] = 3;
    Graph[1][6] = 0;

    Graph[2][0] = 1;
    Graph[2][1] = 2;
    Graph[2][2] = 0;
    Graph[2][3] = 1;
    Graph[2][4] = 3;
    Graph[2][5] = 0;
    Graph[2][6] = 0;

    Graph[3][0] = 2;
    Graph[3][1] = 0;
    Graph[3][2] = 1;
    Graph[3][3] = 0;
    Graph[3][4] = 0;
    Graph[3][5] = 0;
    Graph[3][6] = 1;

    Graph[4][0] = 0;
    Graph[4][1] = 0;
    Graph[4][2] = 3;
    Graph[4][3] = 0;
    Graph[4][4] = 0;
    Graph[4][5] = 2;
    Graph[4][6] = 0;

    Graph[5][0] = 0;
    Graph[5][1] = 3;
    Graph[5][2] = 0;
    Graph[5][3] = 0;
    Graph[5][4] = 2;
    Graph[5][5] = 0;
    Graph[5][6] = 1;

    Graph[6][0] = 0;
    Graph[6][1] = 0;
    Graph[6][2] = 0;
    Graph[6][3] = 1;
    Graph[6][4] = 0;
    Graph[6][5] = 1;
    Graph[6][6] = 0;

    u = 0;
    Dijkstra(Graph, n, u);