对称矩阵的存储练习，c/c++描述

  从存储对称矩阵的一维数组里读取原对称矩阵的元素值，需要经过精巧的行列公式计算。乘法里，对矩阵元素的初始化是需要的，可见建立矩阵后，编译器自动对其初始化了么？

#include<iostream>
#include<stdio.h>
using namespace std;
#define ONEDIMENLENG 10
#define TWODIMENLENG 4

int elemenValue(int array[ONEDIMENLENG],int rank,int column) {
	   // 按下三角矩阵存储。要求 rank  >= column,否则求其转置a(j,i)
	if (rank >= column)
		return array[rank * (rank + 1) / 2 + column];
	else
		return array[column * (column +1) / 2 + rank];
}
void add(int arrayA[],int arrayB[],int arrayAdd[][TWODIMENLENG]) {
	for (int rank = 0; rank < TWODIMENLENG; rank++)
		for (int column = 0; column < TWODIMENLENG; column++)
			arrayAdd[rank][column] = elemenValue(arrayA, rank, column) +
			elemenValue(arrayB,rank,column);
}

void multipl(int arrayA[ONEDIMENLENG],	int arrayB[ONEDIMENLENG],
		int arrayMultipl[TWODIMENLENG][TWODIMENLENG]) {
	int rank, column,i;
	for (rank = 0; rank < TWODIMENLENG; rank++)
		for (column = 0; column < TWODIMENLENG; column++) {
			arrayMultipl[rank][column] = 0;
			for (i = 0; i < TWODIMENLENG; i++)
				arrayMultipl[rank][column] += elemenValue(arrayA, rank, i) *
				elemenValue(arrayB, i, column);
		}
}

void displaySymmetricArray(int array[ONEDIMENLENG]) {
	for (int rank = 0; rank < TWODIMENLENG; rank++) {
		for (int column = 0; column < TWODIMENLENG; column++)
			printf("%5d",elemenValue(array,rank,column));
		cout << endl << endl;
	}
}
void displayMetrix(int array[TWODIMENLENG][TWODIMENLENG]) {
	for (int i = 0; i < TWODIMENLENG; i++) {
		for (int j = 0; j < TWODIMENLENG; j++)
			printf("%5d", array[i][j]);
		cout << endl << endl;
	}
}

int main() {
	int arrayA[] = {1,1,2,2,3,4,4,5,6,7};
	int arrayB[] = {1,1,1,1,1,1,1,1,1,1};
	int arrayAdd[TWODIMENLENG][TWODIMENLENG];
	int arrayMultip[TWODIMENLENG][TWODIMENLENG];

	add(arrayA,arrayB,arrayAdd);
	multipl(arrayA,arrayB,arrayMultip);

	cout << "array A ;" << endl;
	displaySymmetricArray(arrayA);

	cout <<endl<< "array B ;" << endl;
	displaySymmetricArray(arrayB);

	cout << endl << "array A + B :" << endl;
	displayMetrix(arrayAdd);

	cout << endl << "array A * B :" << endl;
	displayMetrix(arrayMultip);

	return 0;
}

测试结果如下，和课本是一致的


谢谢