Here we will see one problem. We have one array. our task is to find those elements whose frequencies are more than 1. Suppose the elements are {1, 5, 2, 5, 3, 1, 5, 2, 7}. Here 1 has occurred 2 times, 5 has occurred 3 times and 2 has occurred three times, others have occurred only once. So the output will be {1, 5, 2}
Algorithm
moreFreq(arr, n)
Begin define map with int type key and int type value for each element e in arr, do increase map.key(arr).value done for each key check whether the value is more than 1, then print the key End
Example
#include <iostream> #include <map> using namespace std; void moreFreq(int arr[], int n){ map<int, int> freq_map; for(int i = 0; i<n; i++){ freq_map[arr[i]]++; //increase the frequency } for (auto it = freq_map.begin(); it != freq_map.end(); it++) { if (it->second > 1) cout << it->first << " "; } } int main() { int arr[] = {1, 5, 2, 5, 3, 1, 5, 2, 7}; int n = sizeof(arr)/sizeof(arr[0]); cout << "Frequency more than one: "; moreFreq(arr, n); }
Output
Frequency more than one: 1 2 5