三维矩阵的实现

#ifndef _MATRIX_H_#define _MATRIX_H_template<typename Type>void Matrix3D(Type*** &matrix, int nDepth, int nHeight, int nWidth){int nPlaneSize =nDepth * nHeight * nWidth * sizeof(Type);int nPlaneIndexSize = nDepth * sizeof(Type***);int nIndexSize = nDepth * nHeight * sizeof(Type**);matrix = NULL;matrix = (Type***) new char[nPlaneSize + nPlaneIndexSize + nIndexSize];// 预分配空间（平面索引区，数据索引区，数据区）,平面索引区的首地址为matrixType** startDataIndex = NULL; // 数据索引区的首地址startDataIndex = (Type**)((char*)matrix + nDepth * sizeof(Type***));Type* startData = NULL; // 数据区首地址startData = (Type*)((char*)startDataIndex + nHeight * nDepth * sizeof(Type**));memset(startData, 0, nHeight * nWidth * nDepth * sizeof(Type));// 索引平面int i = 0, j = 0;Type*** planeIndex = matrix;Type** plane = startDataIndex;for (i=0; i<nDepth; i++){*(planeIndex + i) = plane;plane += nHeight;}plane = startDataIndex;// 索引数据Type* data = startData;for (i=0; i<nDepth; i++){for (j=0; j<nHeight; j++){*(plane+j) = data;data += nWidth;}plane += nHeight;}}#endif

代码是对算法的最好描述，所以不准备对设计思路多费口舌了。

下面是测试用的

#include <iostream>#include "matrix.h"using std::endl;using std::cout;using std::cin;int main(){double ***pd = NULL;int nHeight, nWidth, nDepth;nHeight = nWidth = 3;nDepth = 5;Matrix3D(pd, nDepth, nHeight, nWidth);double val = 0;for (int k = 0; k<nDepth; k++){for (int i = 0; i<nHeight; i++){for (int j=0; j<nWidth; j++){pd[k][i][j] = val++;cout << pd[k][i][j]<<"/t";}cout << endl;}cout << endl;}return 0;}