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Palindrome
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//Способ с перебором массива | |
function isPalindrome(s){ | |
s = s.toLowerCase().replace(/[^а-яё]/g, ""); | |
for (var i = 0; i < s.length / 2; i++){ | |
var b = s[i]; | |
var e = s[s.length - 1 - i]; | |
if (b !== e) | |
{ | |
return false; | |
} | |
} | |
return true; | |
} | |
//Способ с обработкаой строк, в несколько раз дольше способа с перебором | |
function isPalindrome2(s){ | |
s = s.toLowerCase().replace(/[^а-яё]/g, ""); | |
var l = s.length / 2; | |
var s1 = s.substr(0, l); | |
var s2 = s.substr(l, s.length - 1); | |
//удалить средний символ, если исходная строка содержит нечетное количество символов | |
if (s2.length > s1.length){ | |
s2 = s2.substr(1); | |
} | |
s2 = s2.split("").reverse().join(""); | |
return s1 === s2; | |
} | |
//Test | |
var s = new Array(1000000).join("Аа"); | |
console.time("1"); | |
console.log(isPalindrome(s)); //137.287ms | |
console.timeEnd("1"); | |
console.time("2"); | |
console.log(isPalindrome2(s)); //525.857ms | |
console.timeEnd("2"); |
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