LeetCode(27)-Remove Element

题目

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 in place with constant memory.

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

Example:
Given input array nums = [3,2,2,3], val = 3

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

Hint:

Try two pointers.
Did you use the property of "the order of elements can be changed"?Show More Hint

思路

首先题意是要把数组中的给定值移到后面，同时返回最后一个非给定值的坐标

设置两个变量i，j，i负责遍历数组，比较和给定值相同不

如果不同，把nums【j++】 = nums【i】；相同不做，j负责指向最后一个非给定值的坐标
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代码

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