首页 > 代码库 > [LeetCode] Search a 2D Matrix

[LeetCode] Search a 2D Matrix

2024-07-08 20:47:42   218人阅读

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:

  • Integers in each row are sorted from left to right.
  • The first integer of each row is greater than the last integer of the previous row.

 

For example,

Consider the following matrix:

[  [1,   3,  5,  7],  [10, 11, 16, 20],  [23, 30, 34, 50]]

Given target = 3, return true.

编程思想：从矩阵的右上角的元素开始与目标元素比较大小，矩阵右上角元素，比目标元素大的，删除矩阵右上角元素所在列，否则删除所在行，直到找到目标元素或者删除所有行列。

class Solution {public:    bool searchMatrix(vector<vector<int> > &matrix, int target) {        if(matrix.empty())           return false;                   int rows = matrix.size();        int columns = matrix[0].size();                int row = 0,column = columns-1;        while(row<rows && column>=0){            if(matrix[row][column]==target)               return true;            else if(matrix[row][column]>target)               column--;            else               row++;        }//end while        return false;    }};

 


联系
我们