机器视觉-笔试题2 统计直方图

不允许用opencv的Mat，要求手写代码；

#include<iostream>
#include<vector>
using namespace std;

//随机数头文件
#include <stdlib.h> 
#include <stdio.h> 
#include <time.h> 



#define MAX_PIXEL_VALUE 25

namespace MY
{
    class Mat
    {
    public:
        Mat();
        Mat(int rows, int cols);
        int rows() const
        {
            return rows_;
        }
        int cols() const
        {
            return cols_;
        }
        ~Mat();
        bool empty() const
        {
            return image.empty();
        }
        int get(int rows, int cols) const
        {
            return image[rows][cols];
        }
    public:vector<vector<int>> image;
    private:
        int rows_;
        int cols_;
    };
    Mat::Mat(int rows, int cols) :rows_(rows), cols_(cols)
    {
        srand((unsigned)time(NULL));//随机数种子
        for (int j = 0; j < rows; j++)
        {
            vector<int> temp;
            for (int i = 0; i < cols; i++)
            {
                temp.push_back(rand() % (MAX_PIXEL_VALUE+1));//【0，26)
            }
            image.push_back(temp);
        }
    }
    Mat::Mat()
    {
    }

    Mat::~Mat()
    {
    }
    
    //统计直方图
    void ImHist(const vector<vector<int>>& vecs)
    {
        if (vecs.empty())
        {
            cout << "empty! " << endl;
            return;
        }
        else
        {
            int rows = vecs.size();
            int cols = vecs[0].size();
            vector<int> imhist((MAX_PIXEL_VALUE + 1), 0);
            for (int j = 0; j < rows; j++)
            {
                for (int i = 0; i < cols; i++)
                {
                    imhist[vecs[j][i]]++;
                }
            }
            // 直方图，控制台显示
            for(auto& pixelvalue:imhist)
            {
                for (int i = 0; i < pixelvalue; i++)
                {
                    cout << "-";
                }
                cout << endl;
            }
        }
    }
    //显示Mat
    void PrintMat(const Mat& mat) //const 对象只能访问const成员函数
    {
        if (mat.empty())
        {
            cout << "empty! " << endl;
            return;
        }
        else
        {
            for (int j = 0; j < mat.rows(); j++)
            {
                for (int i = 0; i < mat.cols(); i++)
                {
                    cout << mat.get(j,i) << " ";
                    cout.width(2);
                }
                cout << endl;
            }
        }

    }
}


int main()
{
    MY::Mat matrix(30, 30);
    vector<vector<int>> image = matrix.image;
    MY::PrintMat(matrix);
    MY::ImHist(image);
    return 1;
}

 凑合显示下直方图