56 lines
1.2 KiB
C++
56 lines
1.2 KiB
C++
#include "walltime.h"
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#include <iostream>
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#include <random>
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#define VEC_SIZE 1000000000
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#define BINS 16
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using namespace std;
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int main() {
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double time_start, time_end;
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// Initialize random number generator
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unsigned int seed = 123;
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float mean = BINS / 2.0;
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float sigma = BINS / 12.0;
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std::default_random_engine generator(seed);
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std::normal_distribution<float> distribution(mean, sigma);
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// Generate random sequence
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// Note: normal distribution is on interval [-inf; inf]
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// we want [0; BINS-1]
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int *vec = new int[VEC_SIZE];
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for (long i = 0; i < VEC_SIZE; ++i) {
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vec[i] = int(distribution(generator));
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if (vec[i] < 0)
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vec[i] = 0;
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if (vec[i] > BINS - 1)
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vec[i] = BINS - 1;
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}
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// Initialize histogram
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// Set all bins to zero
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long dist[BINS];
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for (int i = 0; i < BINS; ++i) {
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dist[i] = 0;
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}
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time_start = wall_time();
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// Compute histogram
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for (long i = 0; i < VEC_SIZE; ++i) {
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dist[vec[i]]++;
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}
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time_end = wall_time();
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// Write results
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for (int i = 0; i < BINS; ++i) {
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cout << "dist[" << i << "]=" << dist[i] << endl;
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}
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cout << "Time: " << time_end - time_start << " sec" << endl;
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delete[] vec;
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return 0;
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}
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