sort

sort.cpp

+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
+#include <omp.h>
+#include <vector>
+
+using namespace std;
+
+int n, m[400100];
+int thread_count;
+vector<int> sub[600];
+
+void bucketSort(void) {
+        int my_rank = omp_get_thread_num();
+	int size = sub[my_rank].size();
+
+	for (int i = 0; i < size; i++) {
+                for (int j = i+1; j < size; j++) {
+                        if (sub[my_rank][i] > sub[my_rank][j]) {
+                                int tmp = sub[my_rank][i];
+                                sub[my_rank][i] = sub[my_rank][j];
+                                sub[my_rank][j] = tmp;
+                        }
+                }
+        }
+}
+
+int getSection(int x) {
+	int width = n / thread_count;
+	if (x) {
+		x--;
+	}
+
+	return x/width;
+}
+
+int main(int argc, char *argv[]) {
+        thread_count = strtol(argv[1], NULL, 10);
+
+        scanf("%d", &n);
+        for (int i = 0; i < n; i++) {
+                m[i] = rand() % n;
+        }       
+
+	time_t startTime, endTime;
+	time(&startTime);
+        for (int i = 0; i < n; i++) {
+                sub[getSection(m[i])].push_back(m[i]);
+        }
+
+        #pragma omp parallel num_threads(thread_count)
+        bucketSort();
+        #pragma omp barrier
+
+        vector<int> result;
+        for (int i = 0; i < thread_count; i++) {
+                int size = sub[i].size();
+                for (int j = 0; j < size; j++) {
+                        result.push_back(sub[i][j]);
+                }
+        }       
+
+	time(&endTime);
+	double diff = difftime(endTime, startTime);
+	printf("%lf\n", diff);
+        printf("\n");
+
+	return 0;
+}