Kami mendapat graf dengan bucu sumber dalam graf. Kita perlu mencari laluan terpendek dari bucu sumber ke semua bucu lain graf.
Algoritma Dijikstra ialah algoritma tamak untuk mencari laluan terpendek dari puncak sumber ke nod punca graf ke nod punca graf.
Step 1 : Create a set shortPath to store vertices that come in the way of the shortest path tree. Step 2 : Initialize all distance values as INFINITE and assign distance values as 0 for source vertex so that it is picked first. Step 3 : Loop until all vertices of the graph are in the shortPath. Step 3.1 : Take a new vertex that is not visited and is nearest. Step 3.2 : Add this vertex to shortPath. Step 3.3 : For all adjacent vertices of this vertex update distances. Now check every adjacent vertex of V, if sum of distance of u and weight of edge is elss the update it.
Berdasarkan algoritma ini marilah kita mencipta program.
#include <limits.h> #include <stdio.h> #define V 9 int minDistance(int dist[], bool sptSet[]) { int min = INT_MAX, min_index; for (int v = 0; v < V; v++) if (sptSet[v] == false && dist[v] <= min) min = dist[v], min_index = v; return min_index; } int printSolution(int dist[], int n) { printf("Vertex Distance from Source\n"); for (int i = 0; i < V; i++) printf("%d \t %d\n", i, dist[i]); } void dijkstra(int graph[V][V], int src) { int dist[V]; bool sptSet[V]; for (int i = 0; i < V; i++) dist[i] = INT_MAX, sptSet[i] = false; dist[src] = 0; for (int count = 0; count < V - 1; count++) { int u = minDistance(dist, sptSet); sptSet[u] = true; for (int v = 0; v < V; v++) if (!sptSet[v] && graph[u][v] && dist[u] != INT_MAX && dist[u] + graph[u][v] < dist[v]) dist[v] = dist[u] + graph[u][v]; } printSolution(dist, V); } int main() { int graph[V][V] = { { 0, 6, 0, 0, 0, 0, 0, 8, 0 }, { 6, 0, 8, 0, 0, 0, 0, 13, 0 }, { 0, 8, 0, 7, 0, 6, 0, 0, 2 }, { 0, 0, 7, 0, 9, 14, 0, 0, 0 }, { 0, 0, 0, 9, 0, 10, 0, 0, 0 }, { 0, 0, 6, 14, 10, 0, 2, 0, 0 }, { 0, 0, 0, 0, 0, 2, 0, 1, 6 }, { 8, 13, 0, 0, 0, 0, 1, 0, 7 }, { 0, 0, 2, 0, 0, 0, 6, 7, 0 } }; dijkstra(graph, 0); return 0; }
Vertex Distance from Source 0 0 1 6 2 14 3 21 4 21 5 11 6 9 7 8 8 15
Atas ialah kandungan terperinci Algoritma laluan terpendek Dijkstra untuk program C/C++. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!