Arrangement of words without changing the relative position of vowel and consonants?
Suppose we have a string with n elements (n < 10). We have to find the number of ways that the string can be arranged without changing the relative position of the vowel and consonants.
The approach is simple. We have to count the number of vowels and consonants in the given string, then we have to find how many ways we can arrange the vowels only, then find the number of ways to arrange the consonant only, after that multiply these two results to get the total ways.
Algorithm
arrangeWayCount(str)
Begin
define an array ‘freq’ to store frequency.
count and place frequency of each characters in freq array. such that freq[‘0’] will hold
frequency of letter ‘a’, freq[1] will hold frequency of ‘b’ and so on.
v := number of vowels, and c := number of consonants in str
vArrange := factorial of v
for each vowel v in [a, e, i, o, u], do
vArrange := vArrange / factorial of the frequency of v
done
cArrange := factorial of c
for each consonant con, do
cArrange := cArrange / factorial of the frequency of con
done
return vArrange * cArrange
End
Example
#include <iostream>
using namespace std;
long long factorial(int n){
if(n == 0 || n == 1)
return 1;
return n*factorial(n-1);
}
long long arrangeWayCount(string str){
long long freq[27] = {0}; //fill frequency array to 0
int v = 0, c = 0;
for (int i = 0; i < str.length(); i++) {
freq[str[i] - 'a']++;
if (str[i] == 'a' || str[i] == 'e' || str[i] == 'i' || str[i] == 'o' || str[i] == 'u') {
v++;
}else
c++;
}
long long arrangeVowel;
arrangeVowel = factorial(v);
arrangeVowel /= factorial(freq[0]); // vowel a
arrangeVowel /= factorial(freq[4]); // vowel e
arrangeVowel /= factorial(freq[8]); // vowel i
arrangeVowel /= factorial(freq[14]); // vowel o
arrangeVowel /= factorial(freq[20]); // vowel u
long long arrangeConsonant;
arrangeConsonant = factorial(c);
for (int i = 0; i < 26; i++) {
if (i != 0 && i != 4 && i != 8 && i != 14 && i != 20)
arrangeConsonant /= factorial(freq[i]); //frequency of all characters except vowels
}
long long total = arrangeVowel * arrangeConsonant;
return total;
}
main() {
string str = "computer";
long long ans = arrangeWayCount(str);
cout << "Possible ways to arrange: " << ans << endl;
}Output
Possible ways to arrange: 720
Published on 01-Aug-2019 11:10:38
