1// spreadsort fully sorted data example.
2//
3// Copyright Steven Ross 2009-2014.
4//
5// Distributed under the Boost Software License, Version 1.0.
6// (See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8
9// See http://www.boost.org/libs/sort for library home page.
10
11#include <boost/sort/spreadsort/spreadsort.hpp>
12#include <time.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <algorithm>
16#include <vector>
17#include <string>
18#include <fstream>
19#include <sstream>
20#include <iostream>
21using namespace boost::sort::spreadsort;
22
23#define DATA_TYPE int
24
25
26//Pass in an argument to test std::sort
27int main(int argc, const char ** argv) {
28 size_t uCount,uSize=sizeof(DATA_TYPE);
29 bool stdSort = false;
30 unsigned loopCount = 1;
31 for (int u = 1; u < argc; ++u) {
32 if (std::string(argv[u]) == "-std")
33 stdSort = true;
34 else
35 loopCount = atoi(nptr: argv[u]);
36 }
37 //Sorts the data once, then times sorting of already-sorted data
38 loopCount += 1;
39 std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
40 if (input.fail()) {
41 printf(format: "input.txt could not be opened\n");
42 return 1;
43 }
44 double total = 0.0;
45 std::vector<DATA_TYPE> array;
46 input.seekg (0, std::ios_base::end);
47 size_t length = input.tellg();
48 uCount = length/uSize;
49 input.seekg (0, std::ios_base::beg);
50 //Conversion to a vector
51 array.resize(new_size: uCount);
52 unsigned v = 0;
53 while (input.good() && v < uCount) // EOF or failure stops the reading
54 input.read(s: reinterpret_cast<char *>(&(array[v++])), n: uSize );
55 //Run multiple loops, if requested
56 for (unsigned u = 0; u < loopCount; ++u) {
57 clock_t start, end;
58 double elapsed;
59 start = clock();
60 if (stdSort)
61 //std::sort(&(array[0]), &(array[0]) + uCount);
62 std::sort(first: array.begin(), last: array.end());
63 else {
64 printf(format: "call\n");
65 //integer_sort(&(array[0]), &(array[0]) + uCount);
66 integer_sort(first: array.begin(), last: array.end());
67 }
68 end = clock();
69 elapsed = static_cast<double>(end - start) ;
70 std::ofstream ofile;
71 if (stdSort)
72 ofile.open(s: "standard_sort_out.txt", mode: std::ios_base::out |
73 std::ios_base::binary | std::ios_base::trunc);
74 else
75 ofile.open(s: "boost_sort_out.txt", mode: std::ios_base::out |
76 std::ios_base::binary | std::ios_base::trunc);
77 if (ofile.good()) {
78 for (unsigned v = 0; v < array.size(); ++v) {
79 ofile.write(s: reinterpret_cast<char *>(&(array[v])), n: sizeof(array[v]) );
80 }
81 ofile.close();
82 }
83 if (u)
84 total += elapsed;
85 }
86 if (stdSort)
87 printf(format: "std::sort elapsed time %f\n", total / CLOCKS_PER_SEC);
88 else
89 printf(format: "spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC);
90 return 0;
91}
92

source code of boost/libs/sort/example/alreadysorted.cpp