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  1. #include <iostream>
  2. #include <vector>
  3. #include <assert.h>
  4.  
  5. #define M 2
  6. #define N 2
  7.  
  8. template <class T>
  9. class MatrixData {
  10. public:
  11.     MatrixData(int xx, int yy) : col(xx), row(yy), Value(xx * yy) {}
  12.     MatrixData(int xx, int yy, const T& vv) : col(xx), row(yy), Value(xx * yy, vv) {}
  13.   friend class Matrix1D;
  14.   // proxy配列クラス
  15.   class Matrix1D {
  16.   public:
  17.     Matrix1D(MatrixData<T>& arr, int xx) : array(arr), XIndex(xx) {}
  18.     Matrix1D(const MatrixData<T>& arr, int xx) : array(arr), XIndex(xx) {}
  19.     T& operator[](int YIndex) {
  20.       return array.Value[array.row * XIndex + YIndex];
  21.     }
  22.   private:
  23.     int XIndex;
  24.     MatrixData<T>& array;
  25.   };
  26.   MatrixData<T> operator*(MatrixData<T>& md) {
  27.     int i, j, k;
  28.     MatrixData<T> tmp(col, md.row);
  29.     T sum;
  30.  
  31.     // row == md.colの時しか乗算は定義出来ない
  32.  
  33.     assert(row == md.col);
  34.  
  35.     for (i = 0; i < row; i++)
  36.       for (j = 0; j < col; j++) {
  37.         sum = 0;
  38.         for (k = 0; k < md.col; k++)
  39.           sum += (*this)[i][k] * md[k][j];
  40.         tmp[i][j] = sum;
  41.       }
  42.  
  43.     return tmp;
  44.   }
  45.   Matrix1D operator[](int Xindex) {
  46.     return Matrix1D(*this, Xindex);
  47.   }
  48.   //行列データを画面に表示する
  49.   void ShowMatrix()
  50.   {
  51.    int i, j;
  52.  
  53.     for (i = 0; i < row; i++) {
  54.       for (j = 0; j < col; j++)
  55.         std::cout << (*this)[i][j] << ' ';
  56.       std::cout << std::endl;
  57.     }
  58.   }
  59.   //行列の第p行と第q行を入れ替える
  60.   void ChangeMatrix(int p, int q)
  61.   {
  62.     int i;
  63.     MatrixData<T> c = *this;
  64.  
  65.     for (i = 0; i < col; i++) {
  66.       c[q][i] = (*this)[p][i];
  67.       c[p][i] = (*this)[q][i];
  68.     }
  69.  
  70.     Value = c.Value;
  71.   }
  72. private:
  73.   std::vector<T> Value;
  74.   int col;
  75.   int row;
  76. };
  77.  
  78. int main(void)
  79. {
  80.   MatrixData<double> a(M, N), b(M, N), c(M, N);
  81.  
  82.   a[0][0] = 1.0;
  83.   a[0][1] = 2.0;
  84.   a[1][0] = 3.0;
  85.   a[1][1] = 4.0;
  86.   b[0][0] = 5.0;
  87.   b[0][1] = 6.0;
  88.   b[1][0] = 7.0;
  89.   b[1][1] = 8.0;
  90.  
  91.   std::cout << std::fixed;
  92.  
  93.   c = a * b;
  94.   c.ShowMatrix();
  95.  
  96.   c.ChangeMatrix(0, 1);
  97.   c.ShowMatrix();
  98. }
  99.  
Success #stdin #stdout 0.02s 2860KB
comments (?)
stdin 
Standard input is empty
stdout 
19.000000 22.000000 
43.000000 50.000000 
43.000000 50.000000 
19.000000 22.000000
https://ideone.com/deJc6
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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