【每日一题】自己解出来后很开心，看到官方得优雅接替，顿时开心不起来了
var removeDuplicates=function(nums) {
if (nums.length <= 1) return nums.length;
let index = 0;
for (let prev = 1; prev < nums.length; prev++) {
if (nums[index] != nums[prev]) {
nums[++index] = nums[prev];
}
}
return index + 1;
}
