34. Find First and Last Position of Element in Sorted Array

最新推荐文章于 2022-07-27 22:53:20 发布

coding_ironboy

最新推荐文章于 2022-07-27 22:53:20 发布

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     vector<int> searchRange(vector<int>& nums, int target) {
        vector<int> ans(2,-1);
        bool f=false,r=false;
        int n=nums.size();
        int i=0,j=n-1;
        while(i<=j) {
            if (nums[i] != target)i++;
            else if (!f) {
                ans[0]=i;
                f = true;
            }
            if (nums[j] != target)j--;
            else if (!r) {
                ans[1]=j;
                r = true;
            }
            if(f && r)break;
        }
        return ans;
    }


    vector<int> searchRange(vector<int>& nums, int target) {
        int start=0,end=nums.size(),mid=0;
        while(start<end) {
            mid=(start+end)/2;
            if(nums[mid]>=target) end=mid;
            else start=mid+1;
        }
        int left=start;
        start=0;end=nums.size();
        while(start<end) {
            mid=(start+end)/2;
            if(nums[mid]>target)  end=mid;
            else start=mid+1;
        }
        int right=start;
        if(left==right) return {-1,-1};
        else return {left,right-1};
    }