三维数组模板类
C:很难蒙混过关的CArray3d三维数组模板类
总时间限制: 1000ms 内存限制: 65536kB
描述
实现一个三维数组模版CArray3D，可以用来生成元素为任意类型变量的三维数组，输出指定结果
#include <iostream>
#include <iomanip>
#include <cstring>
using namespace std;
template <class T>
class CArray3D
{
// 在此处补充你的代码
};
CArray3D<int> a(3,4,5);
CArray3D<double> b(3,2,2);
void PrintA()
{
for(int i = 0;i < 3; ++i) {
cout << "layer " << i << ":" << endl;
for(int j = 0; j < 4; ++j) {
for(int k = 0; k < 5; ++k)
cout << a[i][j][k] << "," ;
cout << endl;
}
}
}
void PrintB()
{
for(int i = 0;i < 3; ++i) {
cout << "layer " << i << ":" << endl;
for(int j = 0; j < 2; ++j) {
for(int k = 0; k < 2; ++k)
cout << b[i][j][k] << "," ;
cout << endl;
}
}
}
int main()
{
int No = 0;
for( int i = 0; i < 3; ++ i ) {
a[i];
for( int j = 0; j < 4; ++j ) {
a[j][i];
for( int k = 0; k < 5; ++k )
a[i][j][k] = No ++;
a[j][i][i];
}
}
PrintA();
memset(a[1],-1 ,20*sizeof(int));
memset(a[1],-1 ,20*sizeof(int));
PrintA();
memset(a[1][1],0 ,5*sizeof(int));
PrintA();
for( int i = 0; i < 3; ++ i )
for( int j = 0; j < 2; ++j )
for( int k = 0; k < 2; ++k )
b[i][j][k] = 10.0/(i+j+k+1);
PrintB();
int n = a[0][1][2];
double f = b[0][1][1];
cout << "****" << endl;
cout << n << "," << f << endl;
return 0;
}
输入
无
输出
等同于样例
样例输入
无
样例输出
layer 0: 0,1,2,3,4, 5,6,7,8,9, 10,11,12,13,14, 15,16,17,18,19, layer 1: 20,21,22,23,24, 25,26,27,28,29, 30,31,32,33,34, 35,36,37,38,39, layer 2: 40,41,42,43,44, 45,46,47,48,49, 50,51,52,53,54, 55,56,57,58,59, layer 0: 0,1,2,3,4, 5,6,7,8,9, 10,11,12,13,14, 15,16,17,18,19, layer 1: -1,-1,-1,-1,-1, -1,-1,-1,-1,-1, -1,-1,-1,-1,-1, -1,-1,-1,-1,-1, layer 2: 40,41,42,43,44, 45,46,47,48,49, 50,51,52,53,54, 55,56,57,58,59, layer 0: 0,1,2,3,4, 5,6,7,8,9, 10,11,12,13,14, 15,16,17,18,19, layer 1: -1,-1,-1,-1,-1, 0,0,0,0,0, -1,-1,-1,-1,-1, -1,-1,-1,-1,-1, layer 2: 40,41,42,43,44, 45,46,47,48,49, 50,51,52,53,54, 55,56,57,58,59, layer 0: 10,5, 5,3.33333, layer 1: 5,3.33333, 3.33333,2.5, layer 2: 3.33333,2.5, 2.5,2, **** 7,3.33333
提示建议做法：
1. a[i][j][k] 这个表达式的第一个[]返回一个内部类的对象，该内部类也重载了[],且返回值为指针。
2. 必要时需重载对象到指针的强制类型转换运算符
来源Guo Wei
主要问题在于需要内存连续且多重【】访问
所以我们在class里内建类，并新建一维数组
注意重定义一下类型转换函数T* (memset用)
#include <iostream>
#include <iomanip>
#include <cstring>
#include<string>
#include<cstdio>
#include<algorithm>
using namespace std;
template <class T>
class CArray3D
{
class CArray2D{
T *p;
int b,c;
public:
CArray2D(){p=new T[1];}
~CArray2D(){
delete [] p;
}
void INIT(int _b,int _c){
b=_b;c=_c;
delete [] p;
p=new T[b*c+1];
}
T* operator [](int x){
return p+c*x;
}
operator T*(){
return p;
}
};
public:
CArray2D *p;
CArray3D(int a,int b,int c){
p=new CArray2D[a];
for(int i=0;i<a;++i) p[i].INIT(b,c);
}
~CArray3D(){
delete [] p;
}
CArray2D& operator [](int x){
return p[x];
}
// 在此处补充你的代码
};
CArray3D<int> a(3,4,5);
CArray3D<double> b(3,2,2);
void PrintA()
{
for(int i = 0;i < 3; ++i) {
cout << "layer " << i << ":" << endl;
for(int j = 0; j < 4; ++j) {
for(int k = 0; k < 5; ++k)
cout << a[i][j][k] << "," ;
cout << endl;
}
}
}
void PrintB()
{
for(int i = 0;i < 3; ++i) {
cout << "layer " << i << ":" << endl;
for(int j = 0; j < 2; ++j) {
for(int k = 0; k < 2; ++k)
cout << b[i][j][k] << "," ;
cout << endl;
}
}
}
int main()
{
int No = 0;
for( int i = 0; i < 3; ++ i ) {
a[i];
for( int j = 0; j < 4; ++j ) {
a[j][i];
for( int k = 0; k < 5; ++k )
a[i][j][k] = No ++;
a[j][i][i];
}
}
PrintA();
memset(a[1],-1 ,20*sizeof(int));
memset(a[1],-1 ,20*sizeof(int));
PrintA();
memset(a[1][1],0 ,5*sizeof(int));
PrintA();
for( int i = 0; i < 3; ++ i )
for( int j = 0; j < 2; ++j )
for( int k = 0; k < 2; ++k )
b[i][j][k] = 10.0/(i+j+k+1);
PrintB();
int n = a[0][1][2];
double f = b[0][1][1];
cout << "****" << endl;
cout << n << "," << f << endl;
return 0;
}
发表评论