Search a 2D Matrix

class Solution {
public:
    bool dfs(vector<vector<int> > &matrix,int target,int n)
    {
        if(n==matrix.size()) return false;
        if(matrix[n][0]>target) return false;
        for(int i=0;i<matrix[n].size();i++)
        {
            if(matrix[n][i]==target) return true;
            if(matrix[n][i]>target) return false;
        }
        return dfs(matrix,target,n+1);
    }
    bool searchMatrix(vector<vector<int> > &matrix, int target) {
        return dfs(matrix,target,0);
    }
};