数组 - 移动零

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var moveZeroes = function(nums) {
    var unZeroIndex = 0;
    
    for (var i = 0 ; i < nums.length ; i++) {
        if (nums[i] !== 0) {
            nums[unZeroIndex] = nums[i];
            unZeroIndex++;
        }
    }

    for (var i = nums.length - 1 ; i >= unZeroIndex ; i--) {
        nums[i] = 0;
    }
    
    return nums;
};

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var moveZeroes = function(nums) {
    var zeroCount = 0;
    for(var i=0; i<nums.length; i++){
       if(nums[i]==0){
           zeroCount ++;
       }else if(zeroCount>0){
           nums[i-zeroCount]=nums[i];
           nums[i] = 0;
       }
    }
};