虽然简洁度跟佳爷完全没法比，至少accepted很开心了
#include <iostream>
#include <string>
using namespace std;
const int maxd = 100003;
char text[maxd];
int mynext[maxd];
void init(int len)
{
for (int i = 0;i < len;i++)
mynext[i] = i+1;
mynext[len] = -1;
}
int main(void)
{
//read
string str;
while (cin >> str)
{
//init next[]
int len=0;
while (str[len] == '['||str[len] == ']'&&str[len] == ' ')len++;
str = str.substr(len);
len = str.length();
init(len);
//core
int old_tail=0;//承接下文,初始化0处理[]happy类似情况
for (int i = 0;i < len;i++)
{
if (str[i] != '['&&str[i] != ']')old_tail = i + 1;
else if (str[i] == '[' && (str[i + 1] != '[' && str[i+1] != ']'&& str[i+1]!=' '))
{
mynext[old_tail] = -1;
int old_head = mynext[0];
mynext[0] = i + 1 + 1;//str[i+1]为第一个输出字符
int j;
for (j = i + 2;str[j] != '['&&str[j] != ']'&&str[j] != ' ';j++);
mynext[j] = old_head;//str[old_head-1]输出的前一个字符为str[j-1]
i = j-1;//跳过插进前面的字符
}
else if(str[i]==']' && (str[i + 1] != '[' && str[i + 1] != ']' && str[i + 1] != ' '))
{
mynext[old_tail] = i + 1 + 1;
}
}
mynext[old_tail] = -1;
//output
for (int i = mynext[0];i != -1;i=mynext[i])
putchar(str[i-1]);
putchar('
');
}
return 0;
}