35. Search Insert Position

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problem

solution

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class Solution {
public:
    int searchInsert(vector<int>& nums, int target) {
        int ret = -1, n= nums.size();
        for(int i=0;i<n;++i){
            if(nums[i]>=target) return i;
        }
        return n;
    }
};
  • normal version
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class Solution {
public:
    int searchInsert(vector<int>& nums, int target) {
        int n = nums.size(), l=0,r=n-1;
        while(l<=r){
            int mid = l+(r-l)/2;
            if(nums[mid] ==target) return mid;
            else if(nums[mid] < target) l = mid+1;
            else r = mid-1;
        }
        return l ;
        
    }
};
  • left bound
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    class Solution {
    public:
        int searchInsert(vector<int>& nums, int target) {
            int n = nums.size(), l=0,r=n;
            while(l<r){
                int mid = l+(r-l)/2;
                if(nums[mid] ==target) return mid;
                else if(nums[mid] < target) l = mid+1;
                else r = mid;
            }
            return l ;
            
        }
    };

analysis

  • option 1
    • time complexity O(n)
    • space complexity O(1)
  • option 2
    • time complexity O(logn)
    • space complexity O(1)