res.js

/**
 * res.js
 * @authors Joe Jiang (hijiangtao@gmail.com)
 * @date    2017-02-23 13:59:15
 * @version $Id$
 */

/**
 * @param {number[]} nums
 * @return {number}
 */
let removeDuplicates = function(nums) {
    let arrlen = nums.length,
    	curInd = 0;

    if (arrlen < 2) {
    	return nums;
    }

    for (let i=1; i<arrlen; i++) {
    	if ( nums[curInd] !== nums[i] ) {
    		curInd++;
    		nums[curInd] = nums[i];
    	}
    }

    return curInd+1;
};