From ae2ecc64f1af8a2a28c756376e84df20a1a96a02 Mon Sep 17 00:00:00 2001
From: bmusuko <bram.musuko@gmail.com>
Date: Sat, 28 Mar 2020 18:29:23 +0700
Subject: [PATCH] init cuda file
---
djikstra_cuda.cu | 144 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 144 insertions(+)
create mode 100644 djikstra_cuda.cu
diff --git a/djikstra_cuda.cu b/djikstra_cuda.cu
new file mode 100644
index 0000000..e4b0a24
--- /dev/null
+++ b/djikstra_cuda.cu
@@ -0,0 +1,144 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <sys/time.h>
+#include <string.h>
+// #include <cuda.h>
+
+#define INFINITY INT_MAX;
+#define MIN(a,b) (((a)<(b))?(a):(b));
+#define MAX(a,b) (((a)>(b))?(a):(b));
+
+void createGraph(int n, int graph[n]){
+ srand(13517032);
+ int val;
+ for(int i=0;i<n;i++){
+ graph[i*n+i] = 0;
+ for(int j=i+1;j<n;j++){
+ val = (rand() % 50) + 1;
+ graph[i*n+j] = val;
+ graph[j*n+i] = val;
+ }
+ }
+}
+
+void printGraph(int n, int graph[n]){
+ for(int i=0;i<n;i++){
+ for(int j=0;j<n;j++){
+ printf("%d ",graph[i*n+j]);
+ }
+ printf("\n");
+ }
+ printf("\n");
+}
+
+__device__
+void djikstra(int graph[],int start,int distance[],int visited[],int n,int answer[]){
+
+ int node;
+ int temp_dist;
+ int min_dist[2]; // node and its distance
+ min_dist[0] = -1;
+ min_dist[1] = INFINITY;
+ for(int i = 0;i<n;i++){
+ if(i == start){
+ visited[i] = true;
+ distance[i] = 0;
+ } else{
+ visited[i] = false;
+ distance[i] = graph[start*n+i];
+ if(distance[i] < min_dist[1]){
+ min_dist[1] = distance[i];
+ min_dist[0] = i;
+ }
+ }
+ }
+
+ // initialized distance with a
+ for(int i = 0;i<n+1;i++){
+ node = min_dist[0];
+ visited[node] = true;
+ distance[node] = min_dist[1];
+ min_dist[0] = -1;
+ min_dist[1] = INFINITY;
+ for (int j=0;j<n;j++){
+ if(visited[j] == 0){
+ temp_dist = MIN(distance[node] + graph[node*n+j],distance[j]);
+ if(temp_dist < min_dist[1]){
+ min_dist[0] = j;
+ min_dist[1] = temp_dist;
+ }
+ if(distance[j] > temp_dist){
+ distance[j] = temp_dist;
+ }
+ }
+
+ }
+ }
+ for(int i=0;i<n;i++){
+ answer[start*n+i] = distance[i];
+
+ }
+}
+
+__global__
+void djikstra_cuda(int graph[]int distance[],int visited[],int n,int answer[])
+{
+ int index = blockIdx.x * blockDim.x + threadIdx.x;
+ int stride = blockDim.x * gridDim.x;
+ for (int i = index; i < n; i += stride){
+ djikstra(graph,i,distance,visited[],n,answer);
+ }
+}
+
+int main(int argc, char** argv){
+
+ if (argc != 2){
+ printf("Invalid argument\n./djikstra <number_of_node>\n");
+ return 0;
+ }
+ FILE* output_file;
+
+ struct timeval st, et;
+ int n = atoi(argv[1]);
+
+ char filename[80];
+ strcpy(filename, "output_");
+ strcat(filename, argv[1]);
+ strcat(filename,".txt");
+ output_file = fopen(filename, "w+");
+
+ int *graph,*distance,*visited, *answer;
+ graph = malloc(n*n*sizeof(int));
+ distance = malloc(n*sizeof(int));
+ visited = malloc(n*sizeof(int));
+ answer = malloc(n*n*sizeof(int));
+ createGraph(n,graph);
+ fprintf(output_file, "GRAPH:\n");
+ for(int i = 0;i<n;i++){
+ for(int j = 0;j<n;j++){
+ fprintf(output_file, "%d ", graph[i*n+j]);
+ }
+ fprintf(output_file, "\n");
+ }
+ fprintf(output_file, "\n\n\n");
+
+ int blockSize = 256;
+ int numBlocks = (n + blockSize - 1) / blockSize;
+
+ gettimeofday(&st,NULL);
+ djikstra_cuda<<<numBlocks, blockSize>>>>(graph,distance,visited,n,answer);
+ gettimeofday(&et,NULL);
+ unsigned long long int elapsed = ((et.tv_sec - st.tv_sec) * 1000000) + (et.tv_usec - st.tv_usec);
+ printf("Djikstra total time: %llu micro seconds\n",elapsed);
+ fprintf(output_file, "Answer:\n");
+ for(int i = 0;i<n;i++){
+ for(int j = 0;j<n;j++){
+ fprintf(output_file, "%d ", answer[i*n+j]);
+ }
+ fprintf(output_file, "\n");
+ }
+ return 0;
+}
+
--
GitLab