LeetCode之路——LeetCode_27_Remove Element

Given an array and a value, 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:

Given nums = [3,2,2,3], val = 3,Your function should return length = 2, with the first two elements of nums being 2.

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思路：使用一次for循环，用index来计数（从0开始），返回的index就是整个数组中非val的值的个数。

class Solution {

    public int removeElement(int[] nums, int val) {   
       int index = 0;        
        for(int i = 0;i < nums.length;i++){ 
            if(nums[i] != val){
            nums[index] = nums[i];
            index++;
            }
        }
        return index;
    }
}