Java 程序检查两个字符串是否互为字谜
原文:https://www . geesforgeks . org/Java-program-to-check-two-string-is-anagram-of-other/
写一个函数检查两个给定的字符串是否是彼此的字谜。字符串的字谜是另一个包含相同字符的字符串，只有字符的顺序可以不同。例如，“abcd”和“dabc”是彼此的字谜。
我们强烈建议您点击此处进行练习，然后再进入解决方案。
方法 1(使用排序):
- 对两个字符串进行排序
- 比较排序后的字符串
下面是上述想法的实现:
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to check whether two strings
// are anagrams of each other
import java.io.*;
import java.util.Arrays;
import java.util.Collections;
class GFG
{
/* Function to check whether two strings
are anagram of each other */
static boolean areAnagram(char[] str1,
char[] str2)
{
// Get lengths of both strings
int n1 = str1.length;
int n2 = str2.length;
// If length of both strings is not
// same, then they cannot be anagram
if (n1 != n2)
return false;
// Sort both strings
Arrays.sort(str1);
Arrays.sort(str2);
// Compare sorted strings
for (int i = 0; i < n1; i++)
if (str1[i] != str2[i])
return false;
return true;
}
// Driver Code
public static void main(String args[])
{
char str1[] = {'t', 'e', 's', 't'};
char str2[] = {'t', 't', 'e', 'w'};
// Function Call
if (areAnagram(str1, str2))
System.out.println(
"The two strings are" +
" anagram of each other");
else
System.out.println(
"The two strings are not" +
" anagram of each other");
}
}
// This code is contributed by Nikita Tiwari.
输出:
The two strings are not anagram of each other
时间复杂度: O(nLogn)
方法 2(计数字符): 该方法假设两个字符串中可能的字符集都很小。在下面的实现中，假设使用 8 位存储字符，并且可能有 256 个字符。
- 为两个字符串创建大小为 256 的计数数组。将计数数组中的所有值初始化为 0。
- 遍历两个字符串的每个字符，并增加相应计数数组中的字符数。
- 比较计数数组。如果两个计数数组相同，则返回 true。
下面是上述想法的实现:
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to check if two strings
// are anagrams of each other
import java.io.*;
import java.util.*;
class GFG
{
static int NO_OF_CHARS = 256;
/* Function to check whether two strings
are anagram of each other */
static boolean areAnagram(char str1[],
char str2[])
{
// Create 2 count arrays and initialize
// all values as 0
int count1[] = new int[NO_OF_CHARS];
Arrays.fill(count1, 0);
int count2[] = new int[NO_OF_CHARS];
Arrays.fill(count2, 0);
int i;
// For each character in input strings,
// increment count in the corresponding
// count array
for (i = 0; i < str1.length &&
i < str2.length; i++)
{
count1[str1[i]]++;
count2[str2[i]]++;
}
// If both strings are of different length.
// Removing this condition will make the
// program fail for strings like "aaca"
// and "aca"
if (str1.length != str2.length)
return false;
// Compare count arrays
for (i = 0; i < NO_OF_CHARS; i++)
if (count1[i] != count2[i])
return false;
return true;
}
// Driver code
public static void main(String args[])
{
char str1[] =
("geeksforgeeks").toCharArray();
char str2[] =
("forgeeksgeeks").toCharArray();
// Function call
if (areAnagram(str1, str2))
System.out.println(
"The two strings are" +
"anagram of each other");
else
System.out.println(
"The two strings are not" +
" anagram of each other");
}
}
// This code is contributed by Nikita Tiwari.
输出:
The two strings are anagram of each other
方法 3(用一个数组计数字符): 上面的实现可以进一步用一个计数数组代替两个。我们可以在 str1 中增加字符计数数组中的值，在 str2 中减少字符计数数组中的值。最后，如果所有计数值都是 0，那么这两个字符串就是彼此的字谜。感谢高手提出这个优化。
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to check if two strings
// are anagrams of each other
class GFG{
static int NO_OF_CHARS = 256;
// Function to check if two strings
// are anagrams of each other
static boolean areAnagram(char[] str1,
char[] str2)
{
// Create a count array and initialize
// all values as 0
int[] count = new int[NO_OF_CHARS];
int i;
// For each character in input strings,
// increment count in the corresponding
// count array
for(i = 0; i < str1.length; i++)
{
count[str1[i] - 'a']++;
count[str2[i] - 'a']--;
}
// If both strings are of different
// length. Removing this condition
// will make the program fail for
// strings like "aaca" and "aca"
if (str1.length != str2.length)
return false;
// See if there is any non-zero
// value in count array
for(i = 0; i < NO_OF_CHARS; i++)
if (count[i] != 0)
{
return false;
}
return true;
}
// Driver code
public static void main(String[] args)
{
char str1[] =
"geeksforgeeks".toCharArray();
char str2[] =
"forgeeksgeeks".toCharArray();
// Function call
if (areAnagram(str1, str2))
System.out.print(
"The two strings are " +
"anagram of each other");
else
System.out.print(
"The two strings are " +
"not anagram of each other");
}
}
// This code is contributed by mark_85
输出:
The two strings are anagram of each other
时间复杂度: O(n) 详情请参考查看两串是否互为字谜整篇文章！
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