7.9 学习记录

目录

704. 二分查找

35.搜索插入位置

34. 在排序数组中查找元素的第一个和最后一个位置

27. 移除元素

977.有序数组的平方

209.长度最小的子数组

59.螺旋矩阵II

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704. 二分查找

704. 二分查找 - 力扣（LeetCode）

class Solution {
public:
    int search(vector& nums, int target) {
        int left = 0,right = nums.size()-1;
        while (left<=right)
        {
            int mid = left+(right-left)/2;
            if (nums[mid]==target)return mid;
            else if(nums[mid]>target) right = mid-1;
            else left = mid+1;
        }
        return -1;
    }
};

35.搜索插入位置

35. 搜索插入位置 - 力扣（LeetCode）

class Solution {
public:
    int searchInsert(vector& nums, int target) {
        int left = 0,right = nums.size()-1;
        while (left<=right)
        {
            int mid = left+(right-left)/2;
            if (nums[mid]==target)return mid;
            else if(nums[mid]>target)right = mid-1;
            else left = mid+1;
        }
        return left;
    }
};

34. 在排序数组中查找元素的第一个和最后一个位置

34. 在排序数组中查找元素的第一个和最后一个位置 - 力扣（LeetCode）

class Solution {
public:
    vector searchRange(vector& nums, int target) {
        int rightBorder = getRightBorder(nums,target);
        if(rightBorder==-1||nums[rightBorder]!=target) return {-1,-1};
        int leftBorder = getLeftBorder(nums,target);
        return {leftBorder,rightBorder};
    }
private:
    int getRightBorder(vector&nums, int target){
        int left = 0,right = nums.size()-1;
        int rightBorder = -1;
        while (left<=right)
        {
            int mid = left+(right-left)/2;
            if (nums[mid]>target)right = mid-1;
            else
            {
                rightBorder = mid;
                left = mid+1;
            }
        }
        return rightBorder;
    }
    int getLeftBorder(vector&nums, int target){
        int left = 0,right = nums.size()-1;
        int leftBorder = -1;
        while (left<=right)
        {
            int mid = left+(right-left)/2;
            if (nums[mid]

27. 移除元素

27. 移除元素 - 力扣（LeetCode）

class Solution {
public:
    int removeElement(vector& nums, int val) {
        int k = 0;
        for(int ii=0;ii

977.有序数组的平方

977. 有序数组的平方 - 力扣（LeetCode）

class Solution {
public:
    vector sortedSquares(vector& nums) {
        int left =0,right = nums.size()-1;
        vector ans(nums.size(),0);
        int i = right;
        while(left<=right)
        {
            if (nums[left]+nums[right]<0)
            {
                ans[i--] = nums[left]*nums[left++];
            }
            else ans[i--] = nums[right]*nums[right--];
        }
        
        return ans;
    }
};

209.长度最小的子数组

209. 长度最小的子数组 - 力扣（LeetCode）

class Solution {
public:
    int minSubArrayLen(int target, vector& nums) {
        int left = 0,right = 0,len  = nums.size();
        int ans =INT_MAX ,amount = 0;
        while(right=target)
            {
                if(right-left+1

59.螺旋矩阵II

59. 螺旋矩阵 II - 力扣（LeetCode）

class Solution {
public:
    vector> generateMatrix(int n) {
        int k = 0;
        int tmp = 1;
        vector>ans(n,vector(n,0));
        while(tmp<=n*n)
        {
            for(int jj=k;jj<=n-1-k;jj++)
            {
                ans[k][jj] = tmp++;
            }
            for (int ii = k+1;ii=k;jj--)
            {
                ans[n-1-k][jj] = tmp++;
            }
            for (int ii = n-k-2;ii>k;ii--)
            {
                ans[ii][k] = tmp++;
            }
            k++;
        }
        if (n%2==1)
        {
            ans[k-1][k-1]=n*n;
        }
        return ans;
    }
};