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.git
Given nums = [3,2,2,3], val = 3, Your function should return length = 2, with the first two elements of nums being 2.
難度:低
分析:給定數組和指定一個目標值,從數組中移除全部跟目標值相等的元素,返回最終元素的長度,注意不要另外分配內存空間。
思路:題目很簡單,直接遍歷數組元素,判斷當前元素是否跟目標值相等,若是不相等,證實當前元素應該留在數組中,有效數組長度自增1,不然爲無效元素,由於只需返回有效數組長度,因此不用刪除元素,跳過此循環便可。github
public int RemoveElement(int[] nums, int val) { int i = 0; for (int j = 0; j < nums.Length; j++) { //若是不相等,有效長度自增1 if (nums[j] != val) { nums[i] = nums[j]; i++; } } return i; }