我正在构建一个类,其中一个变量是一个二维 vector 。我如何设置它以便我有一个初始大小?我尝试了下面的操作,但出现错误,在数字常量之前应为“,”或“...”。另外,我尝试为 pncode 设置值的每一行都出现错误,数组下标的无效类型“[int]”。
这是类:
#ifndef POSTNET_H_
#define POSTNET_H_
#include <iostream>
#include <cstdlib>
#include <string>
#include <vector>
using namespace std;
class postnet
{
private:
vector<vector<int>> pncode(5, vector<int>(5));
void encode(vector<int> zip)
{
for(int i = 0; i < 5; i++)
{
if(zip[i] == 1 || zip[i] == 2 || zip[i] == 3 || zip[i] == 4 || zip[i] == 5 || zip[i] == 6)
pncode[i][0] = 0;
else
pncode[i][0] = 1;
if(zip[i] == 1 || zip[i] == 2 || zip[i] == 3 || zip[i] == 7 || zip[i] == 8 || zip[i] == 9)
pncode[i][1] = 0;
else
pncode[i][1] = 1;
if(zip[i] == 1 || zip[i] == 4 || zip[i] == 5 || zip[i] == 7 || zip[i] == 8 || zip[i] == 0)
pncode[i][0] = 0;
else
pncode[i][0] = 1;
if(zip[i] == 2 || zip[i] == 4 || zip[i] == 6 || zip[i] == 7 || zip[i] == 9 || zip[i] == 0)
pncode[i][0] = 0;
else
pncode[i][0] = 1;
if(zip[i] == 3 || zip[i] == 5 || zip[i] == 6 || zip[i] == 8 || zip[i] == 9 || zip[i] == 0)
pncode[i][0] = 0;
else
pncode[i][0] = 1;
}
}
void decode(vector<int> zip)
{
int zipd[5];
for(int i = 0; i < 5; i++)
{
zipd[0] = pncode[i][0] * 7;
zipd[1] = pncode[i][1] * 4;
zipd[2] = pncode[i][2] * 2;
zipd[3] = pncode[i][3] * 1;
zipd[4] = pncode[i][4] * 0;
for(int j = 0; j < 5; j++)
{
zip[i] += zipd[j];
}
if(zip[i] == 11)
zip[i] = 0;
}
}
public:
postnet()
{
for(int i = 0; i < 5; i++)
for(int j = 0; j < 5; j++)
pncode[i][j] = 0;
}
postnet(vector<int> zip)
{
encode(zip);
}
postnet(vector<vector<int> > pnc)
{
for(int i = 0; i < 5; i++)
for(int j = 0; j < 5; j++)
pncode[i][j] = pnc[i][j];
}
void print_zip()
{
vector<int> zipc(5);
decode(zipc);
for(int i = 0; i < 5; i++)
cout << zipc[i];
cout << endl;
}
void print_pncode()
{
cout << "1";
for(int i = 0; i < 5; i++)
for(int j = 0; j < 5; j++)
cout << pncode[i][j];
cout << "1" << endl;
}
};
#endif /* POSTNET_H_ */
最佳答案
您现在拥有的代码,vector<vector<int>> pncode(5, vector<int>(5));
,对于 C++11 编译器来说就足够了。在那之前,你必须初始化 pncode
在你的构造函数中。 (您可能还需要在尖括号之间添加一个空格;>>
。)
postnet(vector<int> const &zip)
: pncode(5, vector<int>(5))
{
encode(zip);
}
postnet(vector<vector<int> > const &pnc = vector<vector<int> >(5, vector<int>(5)))
{
assert(pnc.size()==5);
for (int i=0;i<pnc.size();++i)
assert(pnc[i].size()==5);
pncode = pnc;
}
我还冒昧地将您的默认构造函数替换为默认参数,将参数类型更改为 const&,并消除了 vector 元素的手动复制。
关于c++ - 将二维 vector 初始化为类变量 C++,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11350112/