48 lines
1.3 KiB
C++
48 lines
1.3 KiB
C++
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// elements with frequency = (3) in a given array
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//time complexity : O(n) || space complexity : O(1)
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#include <bits/stdc++.h>
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#include <iostream>
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using namespace std;
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int main()
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{ // main function begins here
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int size;
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cout << "Enter the size of the array : ";
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cin >> size;
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int *arr = new int[size];
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map<int, int> mp;
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for (int i = 0; i < size; i++)
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{
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cout << "Enter " << i << " th element of array : ";
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cin >> arr[i];
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mp[arr[i]]++; // this simply stores the frequency of each element in this array
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}
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map<int, int>::iterator it; // this is an iterator which is used to iterate all over the map
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int count = 0;
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for (it = mp.begin(); it != mp.end(); it++)
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{
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if ((*it).second == 3) // checks whether element frequency is 3 or not
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{
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count++; // just check how many elements are there which have frequency 3
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if (count == 1)
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{
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cout << "The elements whose frequency is 3 are: ";
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}
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cout << (*it).first << " "; // print the element which satisfy the above condition
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}
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}
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if (count == 0)
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{
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cout << "There is no elements in this array whose frequency is 3."; // special print if there is no such elements
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}
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cout << endl;
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return 0;
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}
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