Javascript 程序检查两个字符串是否互为字谜
原文:https://www . geesforgeks . org/JavaScript-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 描述语言
<script>
// JavaScript program to check whether
// two strings are anagrams of each other
// Function to check whether two strings
// are anagram of each other
function areAnagram(str1,str2)
{
// Get lengths of both strings
let n1 = str1.length;
let n2 = str2.length;
// If length of both strings is not
// same, then they cannot be anagram
if (n1 != n2)
return false;
// Sort both strings
str1.sort();
str2.sort()
// Compare sorted strings
for (let i = 0; i < n1; i++)
if (str1[i] != str2[i])
return false;
return true;
}
// Driver Code
let str1=['t', 'e', 's', 't'];
let str2=['t', 't', 'e', 'w'];
// Function Call
if (areAnagram(str1, str2))
document.write(
"The two strings are" +
" anagram of each other<br>");
else
document.write(
"The two strings are not" +
" anagram of each other<br>");
// This code is contributed by rag2127
</script>
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 描述语言
<script>
// Javascript program to check if two
// strings are anagrams of each other
let NO_OF_CHARS = 256;
/* Function to check whether two strings
are anagram of each other */
function areAnagram(str1, str2)
{
// Create 2 count arrays and initialize
// all values as 0
let count1 = new Array(NO_OF_CHARS);
let count2 = new Array(NO_OF_CHARS);
for(let i = 0; i < NO_OF_CHARS; i++)
{
count1[i] = 0;
count2[i] = 0;
}
let 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].charCodeAt(0)]++;
count2[str1[i].charCodeAt(0)]++;
}
// 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
let str1 =
("geeksforgeeks").split("");
let str2 =
("forgeeksgeeks").split("");
// Function call
if (areAnagram(str1, str2))
document.write(
"The two strings are" +
"anagram of each other<br>");
else
document.write(
"The two strings are not" +
" anagram of each other<br>");
// This code is contributed by avanitrachhadiya2155
</script>
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 描述语言
<script>
// Javascript program to check if two strings
// are anagrams of each other
let NO_OF_CHARS = 256;
// Function to check if two strings
// are anagrams of each other
function areAnagram(str1, str2)
{
// Create a count array and initialize
// all values as 0
let count = new Array(NO_OF_CHARS);
for(let i = 0; i < NO_OF_CHARS; i++)
{
count[i] = 0;
}
let i;
// For each character in input strings,
// increment count in the corresponding
// count array
for(i = 0; i < str1.length; i++)
{
count[str1[i].charCodeAt(0) -
'a'.charCodeAt(0)]++;
count[str2[i].charCodeAt(0) -
'a'.charCodeAt(0)]--;
}
// 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
let str1 =
"geeksforgeeks".split("");
let str2 =
"forgeeksgeeks".split("");
// Function call
if (areAnagram(str1, str2))
document.write(
"The two strings are " +
"anagram of each other");
else
document.write(
"The two strings are " +
"not anagram of each other");
// This code is contributed by unknown2108.
</script>
输出:
The two strings are anagram of each other
时间复杂度: O(n)
更多详情请参考整篇文章检查两个字符串是否为对方的字谜！
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