69. x 的平方根

class Solution {
public:
    int mySqrt(int x) {
        int l=0,r=x;
        while(l<r)
        {
            int mid=(1ll+l+r)>>1;
            if(1ll*mid*mid<=x)l=mid;
            else r=mid-1;
        }
        return l;
    }
};

35. 搜索插入位置

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

1760. 袋子里最少数目的球

 class Solution {
public:
    bool check(vector<int>&nums,int x,int maxOperations)
    {
        int cnt=0;
        int n=nums.size();
        for(int i=0;i<n;i++)
        {
            cnt+=(nums[i]-1)/x;
        }

        return cnt<=maxOperations;
    }
    int minimumSize(vector<int>& nums, int maxOperations) {
        int l=1,r=1e9;
        while(l<r)
        {
            int mid=l+r>>1;
            if(check(nums,mid,maxOperations))r=mid;
            else l=mid+1;
        }
        return l;
    }
};