026删除排序数组中的重复项

#include "000库函数.h"

////////////自解1：逐个筛选在赋值,时间最短36ms
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.size() < 2)return nums.size();
        vector<int>v;
        v.push_back(nums[0]);        
        for (int i = 1, j = 0; i < nums.size(); ++i)
            if (nums[i] != nums[i - 1])
                v.push_back(nums[i]);
        nums = v;
        return nums.size();        
    }
};

//////////////自解2：使用set自动去重48ms
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.size() < 2)return nums.size();
        set<int>v;
        v.insert(nums.begin(), nums.end());
        nums.assign(v.begin(), v.end());
        return nums.size();
    }
};

//////////自解3 使用算法  60ms
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        return std::unique(nums.begin(), nums.end()) - nums.begin();
    }
};

////////////博客解法1  56ms
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.empty()) return 0;
        int pre = 0, cur = 0, n = nums.size();
        while (cur < n) {
            if (nums[pre] == nums[cur]) ++cur;
            else nums[++pre] = nums[cur++];
        }
        return pre + 1;
    }
};
//////////////////博客解法1  56ms
class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.empty()) return 0;
        int j = 0, n = nums.size();
        for (int i = 0; i < n; ++i) {
            if (nums[i] != nums[j]) nums[++j] = nums[i];
        }
        return j + 1;
    }
};

void T026() {
    vector<int>nums = { 0,0,1,1,1,2,2,3,3,4 };
    Solution S;
    cout << S.removeDuplicates(nums) << endl;
    for (int i = 0; i < nums.size(); ++i)
        cout << nums[i] << '	';
    cout << endl;
}