LeetCode 0080 - Remove Duplicates from Sorted Array II
# Hints
- 水题
# 前置题目
LeetCode 0026 - Remove Duplicates from Sorted Array
# 题面
Difficulty | Time Complexity Limit | Extra-Memory Complexity Limit |
---|---|---|
Medium |
Given a sorted array , remove the duplicates in-place such that duplicates appeared at most twice 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 extra memory.
Example 1:
Given nums = [1,1,1,2,2,3],
Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3 respectively.
It doesn't matter what you leave beyond the returned length.
Example 2:
Given nums = [0,0,1,1,1,1,2,3,3],
Your function should return length = 7, with the first seven elements of nums being modified to 0, 0, 1, 1, 2, 3 and 3 respectively.
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 = removeDuplicates(nums);
// 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]);
}
# 题意
给定一个有序数组 ,要求去除其中的重复元素,使得数组中的相同元素至多出现 次。通过引用修改 中的内容,并返回新的 的长度。
# 题解
本题和 LeetCode 0026 基本上没什么区别,只需在其基础上维护一个标记变量来表示当前值是否已经出现过 次即可。
# AC代码
class Solution {
public:
int removeDuplicates(vector<int> & nums) {
// 特判
if (nums.empty()) {
return 0;
}
// 求解
int n = 1;
bool flag = false;
for (int i = 1; i < nums.size(); i ++) {
if (nums[i] != nums[n - 1] || !flag) {
flag = (nums[i] == nums[n - 1]);
nums[n++] = nums[i];
}
}
// 返回
return n;
}
};
- 01
- Reading Papers - Kernel Concurrency06-01
- 02
- Linux Kernel - Source Code Overview05-01
- 03
- Linux Kernel - Per-CPU Storage05-01