剑指offer 第二题
去力扣里测试算法

思路一：

直接暴力遍历二维数组。

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

本地代码：

#include <iostream>
#include <unordered_map>
#include <vector>
using namespace std;
int main()
{
    vector<vector<int> > vect{ { 1, 4, 7, 11, 15 },
                                {2, 5, 8, 12, 19},
                                {3, 6, 9, 16, 22},
                                {10, 13, 14, 17, 24},
                                {18, 21, 23, 26, 30}
                                                };
    int target = 30;
    //cout << vec[0].size() << endl;
    //matrix = [[1, 4, 7, 11, 15], [2, 5, 8, 12, 19], [3, 6, 9, 16, 22], [10, 13, 14, 17, 24], [18, 21, 23, 26, 30]], target = 5
    for (unsigned int i{ 0 }; i < vect.size(); i++)
    {
        for (unsigned int j{ 0 }; j < vect[i].size(); j++)
        {
            cout << vect[i][j] << " ";
            if (vect[i][j] == target) {
                cout << " " << endl;
                cout << "找到了" << " ";
            }
        }
    }
    return 0;
}

思路二：