Quick sorting of OpenMP

# Include <stdio. h> # include <stdafx. h> # include <iostream> # include <stdlib. h> # include <time. h> # include "OMP. H "using namespace STD; // int COUNT = 0; void swap (Int & A, Int & B) // {int TMP; TMP = A; A = B; B = TMP;} void quicksort (int * a, int L, int U) {int I, m, K; If (L> = u) return; M = L; for (I = L + 1; I <= u; I ++) if (a [I] <A [l]) /* Whether we select the first element as the sequence or the last element as the sequence, if we want a sequence from small to large, the worst input // case is from large to small. If we want to get a sequence from large to small, the worst input condition is the sequence from small to large */swap (A [++ m], a [I]); swap (A [L], A [m]); quicksort (A, l m-1); quicksort (a, m + 1, U);} void main (INT argc, char * argv) {omp_set_num_threads (2); // ---------------- set the number of threads to 2, because it is a dual-core CPU int K = 0, I = 0; int m = 0, n = 0; double cost = 0; int Len = 10000; int short_len = Len/2; int B [10000], C [10000], d [5000], E [5000]; // -------- divide B [] into two small arrays and call the fast Sorting Algorithm for them in parallel # pragma OMP parallel default (none) shared (B, c, Len) private (I) // --- this for loop is parallel {Int J = 50000; # pragma OMP for (I = 0; I <Len; I ++) {B [I] = j --; C [I] = j --; // initialize B [], C [] array} clock_t begin = clock (); // ---------------- timing start point # pragma OMP parallel default (none) shared (B, D, E, short_len) Private (I) // --- this for loop is parallel {# pragma OMP for (I = 0; I <short_len; I ++) // --- this for loop is parallel {d [I] = B [I]; // Add the first 5000 numbers of B [] to d [] E [I] = B [I + 5000]; // put the last 5000 of B [] into E [] }}# Pragma OMP parallel default (none) shared (E, D, short_len) // Private (I) ------ parallel region for fast sorting {# pragma OMP parallel sections {# pragma OMP section quicksort (D, 0, short_len-1 ); // sort by d [] # pragma OMP section quicksort (E, 0, short_len-1); // sort by E []} For (; k <Len; k ++) // ---------- merge and sort d [] and e [] into B [] {If (M <short_len & n <short_len) {If (d [N] <= E [m]) {B [k] = d [N]; n ++ ;} else {B [k] = E [m]; m ++ ;}} if (M = short_len | n = short_len) {If (M = short_len) B [k] = E [m]; else B [k] = d [n-1]; k + = 1; break ;}} if (/* m = short_len & */n <short_len) {int TEM = short_len-n; For (INT p = 0; P <tem; P ++) {B [k] = d [N]; n ++; k ++ ;}} else if (/* n = short_len & */m <short_len) {int TEM = short_len-m; For (INT q = 0; q <tem; q ++) {B [k] = E [m]; m ++; k ++; }}// ---------------------------- end of the merge algorithm clock_t end = clock (); // ---------------- cost = (double) (end-begin ); cout <"parallel time" <cost <Endl; // serial start begin = clock (); quicksort (C, 0, len-1); End = clock (); cost = (double) (end-begin); cout <"Serial Time" <cost <Endl; System ("pause ");}

Quick sorting of OpenMP