27. Remove Element

Author: coderbean

src/leetcode/_27_/Main.java

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+package leetcode._27_;
+
+/**
+ * Created by zhangbo54 on 2019-03-04.
+ */
+public class Main {
+    public static void main(String[] args) {
+        Solution solution = new Solution();
+        int[] ints = {0,1,2,2,3,0,4,2};
+        // int[] ints = {3, 2, 2, 3};
+        int i = solution.removeElement(ints, 2);
+        System.out.println(i);
+    }
+}
+

src/leetcode/_27_/Solution.java

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+package leetcode._27_;
+
+class Solution {
+    public int removeElement(int[] nums, int val) {
+        int seat = 0;
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] != val) {
+                nums[seat++] = nums[i];
+            }
+        }
+        return seat;
+    }
+}

src/leetcode/_27_/solution.md

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+### [27\. Remove ElementCopy for Markdown](https://leetcode.com/problems/remove-element/)
+
+Difficulty: **Easy**
+
+
+Given an array _nums_ and a value _val_, remove all instances of that value and return the new length.
+
+Do not allocate extra space for another array, you must do this by **modifying the input array** 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.
+
+It doesn't matter what values are set beyond the returned length.```
+
+**Clarification:**
+
+Confused why the returned value is an integer but your answer is an array?
+
+Note that the input array is passed in by **reference**, which means modification to the input array will be known to the caller as well.
+
+Internally you can think of this:
+
+```
+// nums is passed in by reference. (i.e., without making a copy)
+int len = removeElement(nums, val);
+
+// any modification to nums in your function would be known by the caller.
+// using the length returned by your function, it prints the first len elements.
+for (int i = 0; i < len; i++) {
+    print(nums[i]);
+}```
+
+
+#### Solution
+
+Language: **Java**
+
+```java
+class Solution {
+    public int removeElement(int[] nums, int val) {
+        int seat = 0;
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] != val) {
+                nums[seat++] = nums[i];
+            }
+        }
+        return seat;
+    }
+}
+```
+![](https://ws3.sinaimg.cn/large/006tKfTcgy1g0z3os9l92j30ue0t0djd.jpg)