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