#include <iostream>
#include <string>
#include <vector>
/*
Using STL's string class because the problem does not refer any
limits regarding the number of characters per line.
*/
using namespace std;
int main()
{
string line;
vector<string> lines;
while (getline(cin, line))
{
lines.push_back(line);
}
unsigned int i, u;
unsigned int opening = 1; // 2 if last was opening, 1 if it was closing
for (i = 0; i < (int) lines.size(); i++)
{
for (u = 0; u < (int) lines[u].length(); u++)
{
}
}
return 0;
}
我有那么简单的代码只读取几行(输入文件):
"To be or not to be," quoth the Bard, "that
is the question".
The programming contestant replied: "I must disagree.
To `C' or not to `C', that is The Question!"
然而,我发现它是SEGFAULTing,因为它在第一行(第四个字符)上读取一个''(空格)字符:
(gdb) run < texquotes_input.txt
Starting program: /home/david/src/oni/texquotes < texquotes_input.txt
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b92533 in std::string::length() const () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
我真的不明白为什么,我在循环中没有做任何事情,我只是在循环。
答案 0 :(得分:6)
我已经发现了问题。这是内循环:
for (u = 0; u < (int) lines[u].length(); u++)
{
}
应该是:
for (u = 0; u < (int) lines[i].length(); u++)
{
}
答案 1 :(得分:2)
在另一个答案中,已经发现了索引错字。
我想补充一点,使用基于范围的for
循环这些问题更难以发生,因为循环更加“隐含”:
#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main()
{
string line;
vector<string> lines;
while (getline(cin, line))
{
lines.push_back(line);
}
for ( const auto& currLine : lines )
{
for ( auto ch : currLine )
{
cout << ch;
}
cout << '\n';
}
}