72 lines
1.2 KiB
C++
72 lines
1.2 KiB
C++
/* bsearch.cpp
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* Created: 2023-07-10
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* Author: Aryadev Chavali
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*/
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#include <algorithm>
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#include <cassert>
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#include <cstdlib>
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#include <fstream>
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#include <iostream>
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#include <string>
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#include <vector>
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using std::cin;
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using std::cout;
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using std::endl;
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using std::ostream;
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using std::string;
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using std::vector;
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ostream &print_arr(ostream &os, std::vector<int> &arr)
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{
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os << "[";
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for (size_t i = 0; i < arr.size(); ++i)
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os << arr[i] << (i == arr.size() - 1 ? "" : ",");
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return os << "]";
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}
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int bsearch(int n, std::vector<int> arr)
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{
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int l = 0;
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int u = arr.size() - 1;
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while (l <= u)
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{
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int midpoint = l + ((u - l) / 2);
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int val = arr[midpoint];
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if (val == n)
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{
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return midpoint;
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}
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else if (val > n)
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{
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u = midpoint - 1;
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}
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else
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{
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l = midpoint + 1;
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}
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}
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return -1;
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}
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int main(int argc, char *argv[])
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{
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std::ifstream input(argc > 1 ? argv[1] : "bsearch.txt");
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std::vector<int> arr;
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for (std::string line; std::getline(input, line);
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arr.push_back(std::stoi(line)))
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continue;
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std::sort(std::begin(arr), std::end(arr));
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for (size_t i = 0; i < arr.size(); ++i)
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{
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int index = bsearch(arr[i], arr);
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assert(index == (int)i);
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}
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return 0;
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}
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