给定字符串小写英文字母。任务是检查字符串中不同字符的计数是否为质数。
例子：
Input : str = "geeksforgeeks"
Output :Yes
Explanation: The number of distinct characters in the
string is 7, and 7 is a prime number.
Input : str ="geeks"
Output : No 在这个问题中，首先我们必须计算字符串的不同字符。我们将使用地图存储每个字母的频率。下一步是计算不同字符的数量，并检查数字是否为质数。
如果数字是素数，我们将打印“是”，否则打印“否”。
下面是上述方法的实现：
C++
// C++ program to check whether count of
// distinct characters in a string
// is Prime or not
#include
using namespace std;
// Find whether a number is prime or not
bool isPrime(int n)
{
int i;
// 1 is not prime
if (n == 1)
return false;
// check if there is any factor or not
for (i = 2; i <= sqrt(n); i++) {
if (n % i == 0)
return false;
}
return true;
}
// Count the distinct characters in a string
int countDistinct(string s)
{
// create a map to store the
// frequency of characters
unordered_map m;
// traverse the string
for (int i = 0; i < s.length(); i++) {
// increase the frequency of character
m[s[i]]++;
}
return m.size();
}
// Driver code
int main()
{
string str = "geeksforgeeks";
if (isPrime(countDistinct(str)))
cout << "Yes" << endl;
else
cout << "No" << endl;
return 0;
} Java
// Java program to check whether count of
// distinct characters in a string
// is Prime or not
import java.util.*;
class GFG
{
// Find whether a number is prime or not
static boolean isPrime(int n)
{
int i;
// 1 is not prime
if (n == 1)
return false;
// check if there is any factor or not
for (i = 2; i <= Math.sqrt(n); i++)
{
if (n % i == 0)
return false;
}
return true;
}
// Count the distinct characters in a string
static int countDistinct(String s)
{
// create a map to store the
// frequency of characters
Set m = new HashSet();
// traverse the string
for (int i = 0; i < s.length(); i++)
{
// increase the frequency of character
m.add(s.charAt(i));
}
return m.size();
}
// Driver code
public static void main(String []args)
{
String str = "geeksforgeeks";
if (isPrime(countDistinct(str)))
System.out.println("Yes");
else
System.out.println("No");
}
}
// This code is contributed by ihritik Python 3
# Python 3 program to check whether
# count of distinct characters in a
# string is Prime or not
# from math library import
# sqrt method
from math import sqrt
# Find whether a number
# is prime or not
def isPrime(n) :
# 1 is not prime
if n == 1 :
return False
# check if there is any
# factor or not
for i in range(2, int(sqrt(n)) + 1) :
if n % i == 0 :
return False
return True
# Count the distinct characters
# in a string
def countDistinct(s) :
# create a dictionary to store
# the frequency of characters
m = {}
# dictionary with keys and its
# initialize with value 0
m = m.fromkeys(s, 0)
# traverse the string
for i in range(len(s)) :
# increase the frequency
# of character
m[s[i]] += 1
return len(m.keys())
# Driver code
if __name__ == "__main__" :
str = "geeksforgeeks"
if isPrime(countDistinct(str)) :
print("Yes")
else :
print("No")
# This code is contributed
# by ANKITRAI1C#
// C# program to check whether count of
// distinct characters in a string
// is Prime or not
using System;
using System.Collections.Generic;
class GFG
{
// Find whether a number is prime or not
static bool isPrime(int n)
{
int i;
// 1 is not prime
if (n == 1)
return false;
// check if there is any factor or not
for (i = 2; i <= Math.Sqrt(n); i++)
{
if (n % i == 0)
return false;
}
return true;
}
// Count the distinct characters in a string
static int countDistinct(String s)
{
// create a map to store the
// frequency of characters
HashSet m = new HashSet();
// traverse the string
for (int i = 0; i < s.Length; i++)
{
// increase the frequency of character
m.Add(s[i]);
}
return m.Count;
}
// Driver code
public static void Main(String []args)
{
String str = "geeksforgeeks";
if (isPrime(countDistinct(str)))
Console.WriteLine("Yes");
else
Console.WriteLine("No");
}
}
// This code has been contributed by 29AjayKumar Javascript
Python3
# Python program for the above approach
from collections import Counter
from math import sqrt as sqrt
def isPrime(n):
# 1 is not prime
if n == 1:
return False
# check if there is any
# factor or not
for i in range(2, int(sqrt(n)) + 1):
if n % i == 0:
return False
return True
# Function to count the number of distinct
# characters present in the string
# str and check whether it is prime
def countDis(str):
# Stores all frquencies
freq = Counter(str)
# Return the size of the freq dictionary
if(isPrime(len(freq))):
return True
else:
return False
# Driver Code
if __name__ == "__main__":
# Given string S
S = "geeksforgeeks"
print(countDis(S))
# This code is contributed by vikkycirus输出：
Yes时间复杂度： O((len(str)) 1/2 )
辅助空间： O(len(str))
方法2：使用计数器函数：
- 使用计数器函数对所有元素的频率进行计数，该频率词典的键数给出计数并检查其是否为质数。
下面是实现：
Python3
# Python program for the above approach
from collections import Counter
from math import sqrt as sqrt
def isPrime(n):
# 1 is not prime
if n == 1:
return False
# check if there is any
# factor or not
for i in range(2, int(sqrt(n)) + 1):
if n % i == 0:
return False
return True
# Function to count the number of distinct
# characters present in the string
# str and check whether it is prime
def countDis(str):
# Stores all frquencies
freq = Counter(str)
# Return the size of the freq dictionary
if(isPrime(len(freq))):
return True
else:
return False
# Driver Code
if __name__ == "__main__":
# Given string S
S = "geeksforgeeks"
print(countDis(S))
# This code is contributed by vikkycirus
输出：
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