C++怎么移除元素

這篇文章主要介紹“C++怎么移除元素”，在日常操作中，相信很多人在C++怎么移除元素問題上存在疑惑，小編查閱了各式資料，整理出簡單好用的操作方法，希望對大家解答”C++怎么移除元素”的疑惑有所幫助！接下來，請跟著小編一起來學(xué)習(xí)吧！

Remove Element 移除元素

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.

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]);
}

這道題讓我們移除一個數(shù)組中和給定值相同的數(shù)字，并返回新的數(shù)組的長度。是一道比較容易的題，只需要一個變量用來計數(shù)，然后遍歷原數(shù)組，如果當(dāng)前的值和給定值不同，就把當(dāng)前值覆蓋計數(shù)變量的位置，并將計數(shù)變量加1。代碼如下：

class Solution {
public:
    int removeElement(vector<int>& nums, int val) {
        int res = 0;
        for (int i = 0; i < nums.size(); ++i) {
            if (nums[i] != val) nums[res++] = nums[i];
        }
        return res;
    }
};

到此，關(guān)于“C++怎么移除元素”的學(xué)習(xí)就結(jié)束了，希望能夠解決大家的疑惑。理論與實踐的搭配能更好的幫助大家學(xué)習(xí)，快去試試吧！若想繼續(xù)學(xué)習(xí)更多相關(guān)知識，請繼續(xù)關(guān)注億速云網(wǎng)站，小編會繼續(xù)努力為大家?guī)砀鄬嵱玫奈恼拢?/p>