Find longest palindrome formed by removing or shuffling chars from string

LongestPalli.js

// Find longest palindrome formed by removing or shuffling chars from string

// Given a string, find the longest palindrome that can be constructed by removing or shuffling characters from the string. 
// Return only one palindrome if there are multiple palindrome strings of longest length.

// Examples:

// Input:  abc
// Output: a OR b OR c

// Input:  aabbcc
// Output: abccba OR baccab OR cbaabc OR
// any other palindromic string of length 6.

// Input:  abbaccd
// Output: abcdcba OR ...

// Input:  aba
// Output: aba


////Analysis
///// I will parse the string and count the number of occurances of each characters in the strings
//// Rules for a string to be a pallindrome:
////   At most only one character can occur odd number of times
////   All other characters must occur even number of times 
////   if 2 characters occur at odd number of times then one of them must drop 1 character to make one of it even
////   create a pallindrome with the set of characters 

function parseAndDropChars(str) {
	var charDict = {};
	for(var i=0;i<str.length;i++) {
		if ( charDict[str[i]] === undefined) {
			charDict[str[i]] =1;
		}
		else {
			var cur_cnt = charDict[str[i]];
			charDict[str[i]] = cur_cnt + 1;
		}
	}
	var odd_cnt=0;
	for(var ch in charDict) {
		if(charDict[ch] % 2 != 0) {
			if(odd_cnt > 0)
				charDict[ch] = charDict[ch] - 1;
			else
				odd_cnt++;
		}
	}
	for(var ch in charDict) {
		if(charDict[ch] == 0)
			delete charDict[ch];
	}
	return charDict;
}

function createPallindrome(charDict) {
	var halfpalli="";
	var pivot="";
	for(var ch in charDict) {
		if(charDict[ch] % 2 == 0) {
			var cl = charDict[ch];
			for(var i=0;i<cl/2;i++) {
				halfpalli = halfpalli + ch;
			}
		}
		else {
			if(charDict[ch] == 1) {
				pivot= ch;
			}
			else {
				var cl = charDict[ch];
				for(var i=0;i<cl/2;i++) {
					halfpalli = halfpalli + ch;
				}
				pivot = ch;
			}
		}
	}
	return halfpalli + pivot + halfpalli.split('').reverse().join('');;
}



function solution(str) {
	return createPallindrome(parseAndDropChars(str));
}


///Verification
console.log(solution("abc"));
console.log(solution("aabbcc"));
console.log(solution("abbaccd"));
console.log(solution("aba"));