我正在尝试创建一个程序,它接受文件的输入,然后将单词存储到一个 vector 中,到目前为止,我已经让它与 std::vector 类一起工作,尽管我想尝试使我的拥有,使用。但是,我遇到了很多错误,但不确定如何解决它们。
错误信息:
main.cpp:43: error: expected constructor, destructor, or type conversion before "Vector"
main.cpp:43: error: expected `;' before "Vector"
main.cpp:47: error: expected constructor, destructor, or type conversion before "Vector"
main.cpp:47: error: expected `;' before "Vector"
main.cpp:55: error: expected constructor, destructor, or type conversion before "Vector"
main.cpp:55: error: expected `;' before "Vector"
main.cpp: In function `int main(int, char**)':
main.cpp:115: error: expected primary-expression before "auto"
main.cpp:115: error: expected `;' before "auto"
main.cpp:116: error: expected primary-expression before "auto"
main.cpp:118: error: no matching function for call to `std::vector<WordInfo, std::allocator<WordInfo> >::push_back(std::string&, int)'
我的代码:
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
struct WordInfo {
string text;
int count;
};
template <class T> class Vector {
public:
typedef T* iterator;
Vector();
iterator begin();
iterator end();
int size();
iterator insert(iterator position, const T& item);
void alloc_new();
private:
T items[1000];
int used;
};
template <class T> Vector<T>::Vector() {
used = 0;
}
template <class T> Vector<T>::iterator Vector<T>::begin() {
return items;
}
template <class T> Vector<T>::iterator Vector<T>::end() {
return items + used;
}
template <class T> int Vector<T>::size() {
return used;
}
template <class T> Vector<T>::iterator Vector<T>::insert(iterator position, const T& item) {
if (used + 1 > items) {
alloc_new();
}
items[position] = item;
used = +1;
}
template <class T> void Vector<T>::alloc_new() {
items = used * 2;
T tmp[] = items;
for (int i = 0; i < used; i++) {
tmp[i] = items[i];
}
delete items;
items = tmp;
}
/*
*
*/
int main(int argc, char** argv) {
enum {
total, unique, individual
} mode = total;
for (int c; (c = getopt(argc, argv, "tu")) != -1;) {
switch (c) {
case 't': mode = total;
break;
case 'u': mode = unique;
break;
case 'i': mode = individual;
break;
}
}
argc -= optind;
argv += optind;
string word;
vector<string> list;
int count = 0;
int count2 = 0;
while (cin >> word) {
count += 1;
if (find(list.begin(), list.end(), word) != list.end()) {
list.push_back(word);
}
}
switch (mode) {
case total: cout << "Total " << count << endl;
break;
case unique: cout << "Unique " << count2 << endl;
break;
case individual:
vector<WordInfo> list;
while (cin >> word) {
if (find(list.begin(), list.end(), word) != list.end()) {
auto = find(list.begin(), list.end(), word);
list.at(auto).count++;
} else {
list.push_back(word, 1);
}
}
break;
}
return 0;
}
如有任何帮助,我们将不胜感激,在此先感谢您!
最佳答案
您需要将返回类型限定为类型名称:
template <class T> typename /* <---- THIS */
Vector<T>::iterator Vector<T>::begin()
{
return items;
}
因为迭代器是一个从属名。不过,在类中实现这些方法可能更为惯用(无论如何,模板方法要求定义位于头文件中)。
还有:
auto = find(list.begin(), list.end(), word);
list.at(auto).count++;
应该是这样的
auto match = find(list.begin(), list.end(), word);
list.at(match - list.begin()).count++;
使用标准库
根据 my comment above ,我建议使用标准库容器做事(至少在尝试实现容器之前)。这是它的样子:
#include <iostream>
#include <map>
#include <algorithm>
#include <numeric>
#include <iterator>
#include <getopt.h>
using namespace std;
int main(int argc, char** argv) {
enum {
total, unique, individual
} mode = total;
for (int c; (c = getopt(argc, argv, "tui")) != -1;) {
switch (c) {
case 't': mode = total;
break;
case 'u': mode = unique;
break;
case 'i': mode = individual;
break;
}
}
argc -= optind;
argv += optind;
map<string, unsigned> tally;
unsigned long total_count = 0;
for_each(
istream_iterator<string>(cin), {},
[&] (std::string const& word) mutable
{
tally[word]++;
total_count++;
}
);
switch (mode) {
case total:
cout << "Total " << total_count << endl;
break;
case unique:
cout << "Unique " << tally.size() << endl;
break;
case individual:
for (auto const& entry: tally)
cout << entry.first << "\t" << entry.second << "\n";
break;
}
}
用input.txt
apple pear jumped over the apple moon
blob the cow blob jumped over the apple moan grumpy dog apple
这是输出:
test -t < input.txt
Total 19
test -u < input.txt
Unique 11
test -i < input.txt
apple 4 blob 2 cow 1 dog 1 grumpy 1 jumped 2 moan 1 moon 1 over 2 pear 1 the 3
关于c++ - vector 类错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19439773/