| 1 | //
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
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| 3 | //
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| 4 | // The contents of this file are covered under the licence agreement in the
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| 5 | // file "LICENCE" distributed with Cforall.
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| 6 | //
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| 7 | // quickSort.c -- In-place concurrent quick-sort: threads are created to partition to a specific depth, then sequential
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| 8 | // recursive-calls are use to sort each partition.
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| 9 | //
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| 10 | // Author : Peter A. Buhr
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| 11 | // Created On : Wed Dec 6 12:15:52 2017
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| 12 | // Last Modified By : Peter A. Buhr
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| 13 | // Last Modified On : Wed Feb 12 18:24:47 2020
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| 14 | // Update Count : 177
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| 15 | //
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| 16 |
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| 17 | #include <fstream.hfa>
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| 18 | #include <stdlib.hfa>
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| 19 | #include <kernel.hfa>
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| 20 | #include <thread.hfa>
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| 21 | #include <string.h> // strcmp
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| 22 |
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| 23 | thread Quicksort {
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| 24 | int * values; // communication variables
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| 25 | int low, high, depth;
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| 26 | };
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| 27 |
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| 28 | void ?{}( Quicksort & qs, int values[], int size, int depth ) {
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| 29 | qs.[values, low, high, depth] = [values, 0, size, depth];
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| 30 | } // Quicksort
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| 31 |
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| 32 | void main( Quicksort & qs ) { // thread starts here
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| 33 | // nested routines: information hiding
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| 34 |
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| 35 | void ?{}( Quicksort & qs, int values[], int low, int high, int depth ) {
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| 36 | qs.values = values; qs.low = low; qs.high = high; qs.depth = depth;
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| 37 | } // Quicksort
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| 38 |
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| 39 | void sort( int values[], int low, int high, int depth ) {
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| 40 | int left, right; // index to left/right-hand side of the values
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| 41 | int pivot; // pivot value of values
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| 42 | int swap; // temporary
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| 43 |
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| 44 | //verify(); // check for stack overflow due to recursion
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| 45 |
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| 46 | // partition while 2 or more elements in the array
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| 47 | if ( low < high ) {
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| 48 | pivot = values[low + ( high - low ) / 2];
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| 49 | left = low;
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| 50 | right = high;
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| 51 |
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| 52 | // partition: move values less < pivot before the pivot and values > pivot after the pivot
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| 53 | do {
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| 54 | while ( values[left] < pivot ) left += 1; // changed values[left] < pivot
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| 55 | while ( pivot < values[right] ) right -= 1;
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| 56 | if ( left <= right ) {
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| 57 | swap = values[left]; // interchange values
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| 58 | values[left] = values[right];
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| 59 | values[right] = swap;
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| 60 | left += 1;
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| 61 | right -= 1;
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| 62 | } // if
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| 63 | } while ( left <= right );
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| 64 |
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| 65 | // restrict number of tasks to slightly greater than number of processors
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| 66 | if ( depth > 0 ) {
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| 67 | depth -= 1;
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| 68 | Quicksort lqs = { values, low, right, depth }; // concurrently sort lower half
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| 69 | Quicksort rqs = { values, left, high, depth }; // concurrently sort upper half
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| 70 | // Quicksort lqs = { values, low, right, depth }; // concurrently sort lower half
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| 71 | // sort( values, left, high, depth ); // concurrently sort upper half
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| 72 | } else {
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| 73 | sort( values, low, right, 0 ); // sequentially sort lower half
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| 74 | sort( values, left, high, 0 ); // sequentially sort upper half
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| 75 | } // if
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| 76 | } // if
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| 77 | } // sort
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| 78 |
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| 79 | with( qs ) {
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| 80 | sort( values, low, high, depth );
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| 81 | } // with
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| 82 | } // main
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| 83 |
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| 84 |
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| 85 | bool convert( int & val, const char * nptr ) { // convert C string to integer
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| 86 | char * eptr;
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| 87 | int temp = strto( nptr, &eptr, 10 ); // do not change val on false
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| 88 | // true => entire string valid with no extra characters
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| 89 | return *nptr != '\0' && *eptr == '\0' ? val = temp, true : false;
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| 90 | } // convert
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| 91 |
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| 92 | void usage( char * argv[] ) {
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| 93 | sout | "Usage:" | argv[0] | "( -s unsorted-file [ sorted-file ] | -t size (>= 0) [ depth (>= 0) ] )";
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| 94 | exit( EXIT_FAILURE ); // TERMINATE!
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| 95 | } // usage
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| 96 |
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| 97 |
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| 98 | int main( int argc, char * argv[] ) {
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| 99 | ifstream & unsortedfile = sin;
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| 100 | ofstream & sortedfile = sout; // default value
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| 101 | int depth = 0, size;
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| 102 |
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| 103 | if ( argc != 1 ) { // do not use defaults
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| 104 | if ( argc < 2 || argc > 4 ) usage( argv ); // wrong number of options
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| 105 | if ( strcmp( argv[1], "-t" ) == 0 ) { // timing ?
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| 106 | &unsortedfile = (ifstream *)0; // no input
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| 107 | choose ( argc ) {
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| 108 | case 4:
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| 109 | if ( ! convert( depth, argv[3] ) || depth < 0 ) usage( argv );
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| 110 | fallthrough;
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| 111 | case 3:
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| 112 | if ( ! convert( size, argv[2] ) || size < 0 ) usage( argv );
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| 113 | } // choose
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| 114 | } else { // sort file
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| 115 | choose ( argc ) {
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| 116 | case 3:
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| 117 | &sortedfile = new( (const char *)argv[2] ); // open the output file
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| 118 | if ( fail( sortedfile ) ) {
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| 119 | serr | "Error! Could not open sorted output file \"" | argv[2] | "\"";
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| 120 | usage( argv );
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| 121 | } // if
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| 122 | fallthrough;
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| 123 | case 2:
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| 124 | &unsortedfile = new( (const char *)argv[1] ); // open the input file
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| 125 | if ( fail( unsortedfile ) ) {
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| 126 | serr | "Error! Could not open unsorted input file \"" | argv[1] | "\"";
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| 127 | usage( argv );
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| 128 | } // if
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| 129 | } // choose
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| 130 | } // if
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| 131 | } // if
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| 132 | sortedfile | nlOff; // turn off auto newline
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| 133 |
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| 134 | enum { ValuesPerLine = 22 }; // number of values printed per line
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| 135 |
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| 136 | if ( &unsortedfile ) { // generate output ?
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| 137 | for () {
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| 138 | unsortedfile | size; // read number of elements in the list
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| 139 | if ( eof( unsortedfile ) ) break;
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| 140 | int * values = alloc( size ); // values to be sorted, too large to put on stack
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| 141 | for ( counter; size ) { // read unsorted numbers
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| 142 | unsortedfile | values[counter];
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| 143 | if ( counter != 0 && counter % ValuesPerLine == 0 ) sortedfile | nl | " ";
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| 144 | sortedfile | values[counter];
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| 145 | if ( counter < size - 1 && (counter + 1) % ValuesPerLine != 0 ) sortedfile | ' ';
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| 146 | } // for
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| 147 | sortedfile | nl;
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| 148 | if ( size > 0 ) { // values to sort ?
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| 149 | Quicksort QS = { values, size - 1, 0 }; // sort values
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| 150 | } // wait until sort tasks terminate
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| 151 | for ( counter; size ) { // print sorted list
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| 152 | if ( counter != 0 && counter % ValuesPerLine == 0 ) sortedfile | nl | " ";
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| 153 | sortedfile | values[counter];
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| 154 | if ( counter < size - 1 && (counter + 1) % ValuesPerLine != 0 ) sortedfile | ' ';
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| 155 | } // for
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| 156 | sortedfile | nl | nl;
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| 157 |
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| 158 | delete( values );
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| 159 | } // for
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| 160 | if ( &unsortedfile != &sin ) delete( &unsortedfile ); // close input/output files
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| 161 | if ( &sortedfile != &sout ) delete( &sortedfile );
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| 162 | } else {
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| 163 | processor processors[ (1 << depth) - 1 ] __attribute__(( unused )); // create 2^depth-1 kernel threads
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| 164 |
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| 165 | int * values = alloc( size ); // values to be sorted, too large to put on stack
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| 166 | for ( counter; size ) { // generate unsorted numbers
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| 167 | values[counter] = size - counter; // descending values
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| 168 | } // for
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| 169 | for ( i; 200 ) { // random shuffle a few values
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| 170 | swap( values[rand() % size], values[rand() % size] );
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| 171 | } // for
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| 172 | {
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| 173 | Quicksort QS = { values, size - 1, depth }; // sort values
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| 174 | } // wait until sort tasks terminate
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| 175 |
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| 176 | // for ( counter; size - 1 ) { // check sorting
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| 177 | // if ( values[counter] > values[counter + 1] ) abort();
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| 178 | // } // for
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| 179 |
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| 180 | delete( values );
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| 181 | } // if
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| 182 | } // main
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| 183 |
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| 184 | // for depth in 0 1 2 3 4 5 ; do echo "sort 500000000 values with ${depth} depth" ; time -f "%Uu %Ss %E %Mkb" a.out -t 500000000 ${depth} ; done
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| 185 |
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| 186 | // Local Variables: //
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| 187 | // tab-width: 4 //
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| 188 | // compile-command: "cfa quickSort.cfa" //
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| 189 | // End: //
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