Create my-tri-diagona-matrix.cpp

Author: JieTrancender

array-matrix/tri-diagona-matrix/my-tri-diagona-matrix.cpp

@@ -0,0 +1,22 @@
+//三对角矩阵的方法
+//采用逐条对角线映射
+
+template <typename anytype>
+anytype TriDiagonaMatrix<anytype>::get(int i, int j) const
+{
+  if( i < 1 || i > n || j < 1  || j > n)
+  {
+    ostream os;
+    os << "The index is not in bounds";
+    return os.c_str();
+  }
+  
+  //确定要返回的元素
+  switch(i - j)
+  {
+    case 1: return m_element[i - 2]; break;             //下对角线
+    case 0: return m_element[n + i - 2]; break;         //主对角线
+    case -1: return m_element[2 * n + i - 2]; break;    //上对角线
+    default: return 0;
+  }
+}