45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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int MAX_N = 100;
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vector<unsigned long long> partition_function(MAX_N + 1, -1);
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int partitioning(int n){
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unsigned long long result = 0;
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for(int k = 1; k <= n; ++k){
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int lower = n - k*(3 * k - 1) / 2;
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int upper = n - k*(3 * k + 1) / 2;
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result += (k % 2 == 0 ? -1 : 1) * ((upper >= 0 ? partition_function[upper] : 0) + (lower >=0 ? partition_function[lower] : 0));
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}
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return result;
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}
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int main(){
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cout << "Hello this is Patrick" << endl;
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auto start = chrono::high_resolution_clock::now();
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// Use partition theory: https://en.wikipedia.org/wiki/Partition_(number_theory)
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// https://kylekizirian.github.io/euler-partition-function.html
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partition_function[0] = 1;
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for(int n = 1; n <= MAX_N; ++n){
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partition_function[n] = partitioning(n);
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}
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// for(unsigned long long i : partition_function){
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// cout << i << " ";
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// } cout << endl;
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cout << partition_function[MAX_N] - 1 << endl;
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auto duration = chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - start);
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cout << (float)duration.count()/1000 << endl;
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return 0;
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}
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