libs/sort/example/reversestringfunctorsample.cpp
// spreadsort string functor reverse sorting example.
//
// Copyright Steven Ross 2009-2014.
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// See http://www.boost.org/libs/sort for library home page.
#include <boost/sort/spreadsort/string_sort.hpp>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>
#include <iostream>
#include <fstream>
#include <string>
using std::string;
using namespace boost::sort::spreadsort;
struct DATA_TYPE {
string a;
};
struct greaterthan {
inline bool operator()(const DATA_TYPE &x, const DATA_TYPE &y) const {
return x.a > y.a;
}
};
struct bracket {
inline unsigned char operator()(const DATA_TYPE &x, size_t offset) const {
return x.a[offset];
}
};
struct getsize {
inline size_t operator()(const DATA_TYPE &x) const{ return x.a.size(); }
};
//Pass in an argument to test std::sort
int main(int argc, const char ** argv) {
std::ifstream indata;
std::ofstream outfile;
bool stdSort = false;
unsigned loopCount = 1;
for (int u = 1; u < argc; ++u) {
if (std::string(argv[u]) == "-std")
stdSort = true;
else
loopCount = atoi(argv[u]);
}
double total = 0.0;
//Run multiple loops, if requested
std::vector<DATA_TYPE> array;
for (unsigned u = 0; u < loopCount; ++u) {
indata.open("input.txt", std::ios_base::in | std::ios_base::binary);
if (!indata) {
printf("input.txt could not be opened\n");
return 1;
}
DATA_TYPE inval;
indata >> inval.a;
while (!indata.eof() ) {
array.push_back(inval);
//Inserting embedded nulls and empty strings
if (!(array.size() % 100)) {
if (inval.a.empty() || !(array.size() % 1000)) {
inval.a = "";
array.push_back(inval);
}
else {
inval.a[0] = '\0';
array.push_back(inval);
}
}
indata >> inval.a;
}
indata.close();
clock_t start, end;
double elapsed;
start = clock();
if (stdSort)
std::sort(array.begin(), array.end(), greaterthan());
else
reverse_string_sort(array.begin(), array.end(), bracket(), getsize(),
greaterthan());
end = clock();
elapsed = static_cast<double>(end - start);
if (stdSort)
outfile.open("standard_sort_out.txt", std::ios_base::out |
std::ios_base::binary | std::ios_base::trunc);
else
outfile.open("boost_sort_out.txt", std::ios_base::out |
std::ios_base::binary | std::ios_base::trunc);
if (outfile.good()) {
for (unsigned u = 0; u < array.size(); ++u)
outfile << array[u].a << "\n";
outfile.close();
}
total += elapsed;
array.clear();
}
if (stdSort)
printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC);
else
printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC);
return 0;
}