Construct K Palindrome Strings

Description

Given a string s and an integer k. You should construct k non-empty palindrome strings using all the characters in s.

Return True if you can use all the characters in s to construct k palindrome strings or False otherwise.

 

Example 1:

Input: s = "annabelle", k = 2
Output: true
Explanation: You can construct two palindromes using all characters in s.
Some possible constructions "anna" + "elble", "anbna" + "elle", "anellena" + "b"

Example 2:

Input: s = "leetcode", k = 3
Output: false
Explanation: It is impossible to construct 3 palindromes using all the characters of s.

Example 3:

Input: s = "true", k = 4
Output: true
Explanation: The only possible solution is to put each character in a separate string.

Example 4:

Input: s = "yzyzyzyzyzyzyzy", k = 2
Output: true
Explanation: Simply you can put all z's in one string and all y's in the other string. Both strings will be palindrome.

Example 5:

Input: s = "cr", k = 7
Output: false
Explanation: We don't have enough characters in s to construct 7 palindromes.

 

Constraints:

• 1 <= s.length <= 10^5
• All characters in s are lower-case English letters.
• 1 <= k <= 10^5

Solution(javascript)

/** 统计出现奇数次字符的个数
 * @param {string} s
 * @param {number} k
 * @return {boolean}
 */
const canConstruct = function (s, k) {
  let oddCount = 0
  const map = {}
  for (const c of s) {
    map[c] = (map[c] || 0) + 1
    if (map[c] % 2 === 0) {
      oddCount--
    } else {
      oddCount++
    }
  }
  return oddCount <= k && s.length >= k
}