0027.Remove Element

1027.Remove Element

Given an array nums and a value val, remove all instances of that value in-place and return the new length.

Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Example 1:

Given nums = [3,2,2,3], val = 3,

Your function should return length = 2, with the first two elements of nums being 2.

It doesn't matter what you leave beyond the returned length.
Example 2:

Given nums = [0,1,2,2,3,0,4,2], val = 2,

Your function should return length = 5, with the first five elements of nums containing 0, 1, 3, 0, and 4.

Note that the order of those five elements can be arbitrary.
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class Solution {
public:
    int removeElement(vector<int>& nums, int val) {
        int len = nums.size(), i, j;
        /*
        for(i=0, j=0; j<len; j++){
            if(nums[j] != val)
                nums[i++] = nums[j];
        }
        */
        for(i=0; i<len; i++){
            if(nums[i] == val)
                nums[i--] = nums[--len];
        }
        return i;
    }
};