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/* Copyright 2011 Erik Gorset. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY Erik Gorset ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Erik Gorset OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. The views and conclusions contained in the software and documentation are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of Erik Gorset. */ #include <iostream> #include <algorithm> #include <time.h> #include <stdio.h> #include <stdlib.h> #include <strings.h> #include <sys/time.h> #define bzero(b,len) (memset((b), '\0', (len)), (void) 0) void insertion_sort(int *array, int offset, int end) { int x, y, temp; for (x=offset; x<end; ++x) { for (y=x; y>offset && array[y-1]>array[y]; y--) { temp = array[y]; array[y] = array[y-1]; array[y-1] = temp; } } } int radix_sort(int *array, int offset, int end, int shift) { int x, y, value, temp; int last[256], pointer[256]; bzero(last, sizeof(int) * 256); for (x=offset; x<end; ++x) { ++last[(array[x] >> shift) & 0xFF]; } last[0] += offset; pointer[0] = offset; for (x=1; x<256; ++x) { pointer[x] = last[x-1]; last[x] += last[x-1]; } for (x=0; x<256; ++x) { while (pointer[x] != last[x]) { value = array[pointer[x]]; y = (value >> shift) & 0xFF; while (x != y) { temp = array[pointer[y]]; array[pointer[y]++] = value; value = temp; y = (value >> shift) & 0xFF; } array[pointer[x]++] = value; } } if (shift > 0) { shift -= 8; for (x=0; x<256; ++x) { temp = x > 0 ? pointer[x] - pointer[x-1] : pointer[0] - offset; if (temp > 50) { radix_sort(array, pointer[x] - temp, pointer[x], shift); } else if (temp > 1) { // std::sort(array + (pointer[x] - temp), array + pointer[x]); insertion_sort(array, pointer[x] - temp, pointer[x]); } } } } int intcmp(const void *aa, const void *bb) { const int *a = (int *)aa, *b = (int *)bb; return (*a < *b) ? -1 : (*a > *b); } int main(int argc, char **argv) { if (sizeof(int) != 4) { std::cerr << "Ooops. sizeof(int) != 4\n"; return 1111; } int N; if (argc != 2 || sscanf(argv[1], "%d", &N) == -1) { std::cerr << "n missing\n"; return 111; } int *array = (int *)malloc(sizeof(int) * N); for (int i=0; i<3; ++i) { long long mtime=0, seconds=0, useconds=0; for( int j = 0; j < 1000; ++j ) { int n = N; srand(1); while (n --> 0) { array[n] = rand(); } struct timeval start, end; gettimeofday(&start, NULL); switch(i) { case 0: std::sort(array, array+N); break; case 1: qsort(array, N, sizeof(int), intcmp); break; case 2: radix_sort(array, 0, N, 24); } gettimeofday(&end, NULL); n = N - 1; while (n --> 0) { if (array[n] > array[n+1]) { std::cerr << "sorting failed\n"; return -1; } } seconds += end.tv_sec - start.tv_sec; useconds += end.tv_usec - start.tv_usec; mtime += seconds * 1000000LL + useconds; } switch(i) { case 0: std::cout << "std::sort " << mtime/1000 << "\n"; break; case 1: std::cout << "qsort " << mtime/1000 << "\n"; break; case 2: std::cout << "radix_sort " << mtime/1000 << "\n"; break; } } return 0; }
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