74. Search a 2D Matrix

static int wing=[]()
{
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    return 0;
}();

class Solution 
{
public:
    bool searchMatrix(vector<vector<int>>& matrix, int target) 
    {
        int szrow=matrix.size();
        if(szrow==0)
            return false;
        int szcol=matrix[0].size(); 
        if(szcol==0)
            return false;
        int lirow=szrow-1,licol=szcol-1;
        int left=0,right=lirow;
        while(left<right)
        {
            int mid=left+((right-left)>>1);
            if(matrix[mid][licol]==target)
                return true;
            else if(matrix[mid][licol]<target)
                left=mid+1;
            else
                right=mid;        
        }
        int row=left;
        if(matrix[row][0]>target)
            return false;
        left=0,right=licol;
        while(left<right)
        {
            int mid=left+((right-left)>>1);
            if(matrix[row][mid]==target)
                return true;
            else if(matrix[row][mid]<target)
                left=mid+1;
            else
                right=mid;
        }
        return matrix[row][left]==target;
    }
};

两个二分查找完事儿