Array | 74. Search a 2D Matrix

题目：搜索二维矩阵

方法1：

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