用于估计句子中单词“is”出现频率的 C# 程序

给定一个字符串作为输入，我们需要用 C# 编写一个程序来计算字符串中单词“is”出现的频率。程序的任务是计算给定单词“is”在字符串中出现的次数，并打印“is”出现的次数。

例子：

Input : string = “The most simple way to prepare for interview is to practice on best computer science portal that is GeeksforGeeks”

Output : Occurrences of “is” = 2 Time

Input : string = “is this is the way to talk to your sister? I don’t know what that is”

Output : Occurrences of “is” = 3 Time

Explanation: The “is” has also occurred in the word “sister” and “this” but we are looking for the word “is” to occur separately. Hence only 3 time.

使用迭代方法

方法：

1. Split the string by spaces
2. Store all the words in an array of strings.
3. Now run a loop at 0 to the length of the array of string and check if our string is equal to the word “is”.
4. If the condition is true increment the count else do not increment it.

代码：

C#

// C# program to count the number
// of occurrence of a "is" in
// the given string
using System;
  
class GFG{
      
static int countOccurrencesOfIs(string str)
{
      
    // Split the string by spaces
    string[] a = str.Split(' ');
    string word = "is";
      
    // Search for "is" in string
    int count = 0;
    for(int i = 0; i < a.Length; i++)
    {    
          
        // If "is" found increase count
        if (word.Equals(a[i]))
            count++;
    }
    return count;
}
  
// Driver code
public static void Main()
{
    string str = "is this is the way to talk to your " + 
                 "sister? I don't know what that is";
    Console.Write(countOccurrencesOfIs(str));
}
}

输出：

3

时间复杂度： O(n) 其中 n 是字符串的长度。