Search a 2D Matrix

 https://leetcode.com/problems/search-a-2d-matrix/

 

(ROWS ARE ONLY SORTED IN ROWS)

(The first integer of each row is greater than the last integer of the previous row.)

class Solution {
public:
    bool searchMatrix(vector<vector<int>>& matrix, int target) {
        if(!matrix.size()) return false;
        int n=matrix.size();
        int m=matrix[0].size();
        int low=0;
        int high=(n*m)-1;
        while(low<=high)
        {
            int mid=low+(high-low)/2;
            if(matrix[mid/m][mid%m]==target) return true;
            else if(matrix[mid/m][mid%m]<target) low=mid+1;
            else high=mid-1;
        }
        return false;
    }
};