我的程序应该根据用户指定的内容对齐输入的文本，到目前为止，我已经了解到它可以更改宽度，但不能对齐文本（左，右，居中）。我见过<iomanip>，但对我而言没有帮助。到目前为止，我得到的代码是
#include <iostream>
#include <sstream>
#include <vector>
#include <iterator>
using namespace std;
string repeatChar(char c, int n) {
string out;
for (; n > 0; n--) {
out.push_back(c);
}
return out;
}
vector<string> getInput() {
vector<string> output;
string line;
cout << "Enter text, empty return will quit the input" << endl;
do {
cout << "> ";
getline(cin, line);
if (line.empty())
continue;
istringstream in(line);
string word;
while (in.good()) {
in >> word;
if (!word.empty())
output.push_back(word);
}
} while (!line.empty());
return output;
}
void printLine(vector<string>::iterator start, vector<string>::iterator end,
int width) {
if(start == end)
return;
int chars = 0;
int spaces = -1;
vector<string> currentLine;
for (; start != end; start++) {
string &word = *start;
int newchars = chars + word.length();
int newspaces = spaces + 1;
if (newchars + newspaces <= width) {
currentLine.push_back(word);
chars = newchars;
spaces = newspaces;
} else
break;
}
cout << '|';
if (spaces <= 0) {
cout << currentLine[0] << repeatChar(' ', (width - chars));
} else {
int spaceWidth = (width - chars) / spaces;
int extraWidth = (width - chars) % spaces;
int i;
for (i = 0; i < currentLine.size() - 1; i++) {
cout << currentLine[i];
cout << repeatChar(' ', spaceWidth);
if (extraWidth > 0) {
cout << ' ';
extraWidth--;
}
}
cout << currentLine[i];
}
cout << '|' << endl;
printLine(start, end, width);
return;
}
void printJustify(vector<string> words, int width) {
cout << '+' << repeatChar('-', width) << '+' << endl;
printLine(words.begin(), words.end(), width);
cout << '+' << repeatChar('-', width) << '+' << endl;
}
int main() {
vector<string> input = getInput();
int maxWidth = 0;
for (int i = 0; i < input.size(); i++) {
maxWidth = (input[i].length() > maxWidth) ? input[i].length() : maxWidth;
}
int width;
do {
cout << "> Enter width of text and align(Left, Right, Center) ";
cin >> width;
if (width == 0)
continue;
width = (width < maxWidth) ? maxWidth : width;
printJustify(input, width);
} while (width > 0);
return 0;
}
但这只会调整宽度，因此我的输出是
Enter text, empty return will quit the input
> There are many types of Parrots in the world,
> for example, African Greys, Macaws,
> Amazons. And much much more.
>
> Enter width of text and align(Left, Right, Center) 30
+------------------------------+
|There are many types of|
|Parrots in the world, for|
|example, African Greys,|
|Macaws, Macaws, Amazons. And|
|much much more. more.|
+------------------------------+
> Enter width of text and align(Left, Right, Center)
这很棒，但是我还需要根据用户输入的内容对齐左，右，居中。我使用过<iomanip>，但没有用。如何使输出左对齐，右对齐或居中对齐？
答案 0 :(得分：1)
又快又脏。但是你应该明白这个主意。
#include <cstdlib>
#include <string>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <algorithm>
std::string get_text(std::istream &is = std::cin)
{
std::string text;
for(std::string line; std::cout << "> ", std::getline(is, line) && !line.empty(); text += ' ' + line);
return text;
}
enum alignment_t { align_left, align_right, align_center };
alignment_t const align_choices[]{ align_left, align_right, align_center };
char const *align_choices_strings[]{ "Left", "Right", "Center" };
std::string extract_line(std::stringstream &ss, int max_width)
{
std::string line;
std::string word;
while ((ss >> word) && line.length() + word.length() + 1 <= max_width)
line += word + ' ';
if(line.length())
line.pop_back();
if (line.length() + word.length() + 1 >= max_width) {
std::stringstream temp;
temp << word;
temp << ss.rdbuf();
ss.swap(temp);
}
return line;
}
void print_box(std::string const &text, int width, alignment_t alignment = align_left, std::ostream &os = std::cout)
{
for (int i = 1; i <= width; ++i)
os << i % 10;
os << '\n';
os << '+' << std::setw(width) << std::setfill('-') << "+\n";
std::stringstream ss;
ss.str(text);
for (std::string line{ extract_line(ss, width - 2) }; line.length(); line = extract_line(ss, width - 2)) {
os << std::setw(1) << '|' << std::setw(width - 2) << std::setfill(' ');
switch (alignment) {
case align_left:
os << std::left << line << std::setw(1) << "|\n";;
break;
case align_right:
os << std::right << line << std::setw(1) << "|\n";;
break;
case align_center:
{
int fill = (width - line.length()) / 2;
os << std::setw(fill + line.length()) << std::right << line << std::setw(width - line.length() - fill) << "|\n";
break;
}
}
}
os << std::setw(1) << '+' << std::setw(width) << std::setfill('-') << std::right << "+\n";
}
int main()
{
std::cout << "Enter text, empty return will quit the input\n";
auto text{ get_text() };
std::cout << "> Enter width of text and align(Left, Right, Center): ";
int width;
std::string alignment;
auto alignment_choice{ std::cbegin(align_choices_strings) };
if (!(std::cin >> width >> alignment) ||
(alignment_choice = std::find(std::cbegin(align_choices_strings), std::cend(align_choices_strings), alignment))
== std::cend(align_choices_strings))
{
std::cerr << "Input error.\n\n";
std::cout << "Bye.\n\n";
return EXIT_FAILURE;
}
print_box(text, width, align_choices[alignment_choice - std::cbegin(align_choices_strings)]);
}
Enter text, empty return will quit the input
> The journey began at
> Folly Bridge near Oxford
> and ended five miles away
> in the village of
> Godstow. During the trip
> Charles Dodgson told the
> girls a story that
> featured a bored little
> girl named Alice who goes
> looking for an adventure.
>
> Enter width of text and align(Left, Right, Center): 25 Right
+-----------------------+
| The journey began at|
| Bridge near Oxford and|
| five miles away in the|
| of Godstow. During the|
| Charles Dodgson told|
| girls a story that|
| a bored little girl|
| Alice who goes looking|
+-----------------------+
Enter text, empty return will quit the input
> The journey began at
> Folly Bridge near Oxford
> and ended five miles away
> in the village of
> Godstow. During the trip
> Charles Dodgson told the
> girls a story that
> featured a bored little
> girl named Alice who goes
> looking for an adventure.
>
> Enter width of text and align(Left, Right, Center): 30 Center
+----------------------------+
| The journey began at Folly|
| near Oxford and ended five|
| away in the village of |
| During the trip Charles |
| told the girls a story that|
| a bored little girl named |
+----------------------------+
Enter text, empty return will quit the input
> The journey began at
> Folly Bridge near Oxford
> and ended five miles away
> in the village of
> Godstow. During the trip
> Charles Dodgson told the
> girls a story that
> featured a bored little
> girl named Alice who goes
> looking for an adventure.
>
> Enter width of text and align(Left, Right, Center): 40 Left
+--------------------------------------+
|The journey began at Folly Bridge |
|Oxford and ended five miles away in |
|village of Godstow. During the trip |
|Dodgson told the girls a story that |
|a bored little girl named Alice who |
+--------------------------------------+
//修复了代码-不再吞下单词和最后一行。但是我拒绝重新运行树时间作为示例输出。