查找字符串中出现的最大和最小字符的Java程序

1 说明

在此程序中，我们需要计算字符串中存在的每个字符，并找出出现的最大和最小字符。

Grass is greener on the other side

在上面的示例中，字符“ a”在字符串中仅出现一次。因此，它是出现的最少字符，并用红色突出显示。字符e在整个字符串中出现的次数最多，即6次。因此，它是出现的最大字符，并用绿色突出显示。

2 算法思路

• 步骤1：开始
• 步骤2： 定义 String str =“grass is greener on the other side”
• 步骤3：初始化minChar，maxChar。
• 步骤4：定义i，j，min，max
• 步骤5：将str转换为char string []。
• 步骤6： SET i = 0。直到i重复步骤7至步骤11
• 步骤7： SET数组freq [i] = 1
• 步骤8：设定j = i + 1。直到j将步骤9重复到步骤10
• 步骤9：如果（string [i] == string [j] && string [i]！=''&& string [i]！='0'），
                则
                freq [i] = freq [i] + 1
                SET string [ j] = 0
• 步骤10： j = j +1
• 步骤11： i = i + 1
• 步骤12：SET min = max = freq[0]
• 步骤13： SET i = 0。直到i重复步骤14至步骤16
• 步骤14：IF(min>freq[i] && freq[i]!=0) then
                min = freq[i]
                minChar[] = string[i]
• 步骤15：IF max is lesser than freq[i]then
                max = freq[i]
                maxChar[] = string[i]
• 步骤16： i = i +1
• 步骤17：打印minChar
• 步骤18：打印maxChar
• 步骤19：结束

3 程序实现

/**
 * 一点教程网： http://www.yiidian.com
 */
public class Characters     
   
   public static void main(String[] args) {    
      String str = "grass is greener on the other side";    
      int[] freq = new int[str.length()];    
      char minChar = str.charAt(0), maxChar = str.charAt(0);    
      int i, j, min, max;            
          
      //Converts given string into character array    
      char string[] = str.toCharArray();    
          
      //Count each word in given string and store in array freq    
      for(i = 0; i < string.length; i++) {    
          freq[i] = 1;    
          for(j = i+1; j < string.length; j++) {    
              if(string[i] == string[j] && string[i] != ' ' && string[i] != '0') {    
                  freq[i]++;    
                      
                  //Set string[j] to 0 to avoid printing visited character    
                  string[j] = '0';    
              }    
          }    
      }    
          
      //Determine minimum and maximum occurring characters    
      min = max = freq[0];    
      for(i = 0; i <freq.length; i++) {    
              
          //If min is greater than frequency of a character     
          //then, store frequency in min and corresponding character in minChar    
          if(min > freq[i] && freq[i] != '0') {    
              min = freq[i];    
              minChar = string[i];    
          }    
          //If max is less than frequency of a character     
          //then, store frequency in max and corresponding character in maxChar    
          if(max < freq[i]) {    
              max = freq[i];    
              maxChar = string[i];    
          }    
      }    
          
      System.out.println("Minimum occurring character: " + minChar);    
      System.out.println("Maximum occurring character: " + maxChar);    
  }    
   

以上代码输出结果为：

Minimum occurring character: a
Maximum occurring character: e