题目：
Given a C++ program, remove comments from it. The program source is an array where source[i] is the i-th line of the source code. This represents the result of splitting the original source code string by the newline character \n.
In C++, there are two types of comments, line comments, and block comments.
The string // denotes a line comment, which represents that it and rest of the characters to the right of it in the same line should be ignored.
The string /* denotes a block comment, which represents that all characters until the next (non-overlapping) occurrence of */should be ignored. (Here, occurrences happen in reading order: line by line from left to right.) To be clear, the string /*/ does not yet end the block comment, as the ending would be overlapping the beginning.
The first effective comment takes precedence over others: if the string // occurs in a block comment, it is ignored. Similarly, if the string /* occurs in a line or block comment, it is also ignored.
If a certain line of code is empty after removing comments, you must not output that line: each string in the answer list will be non-empty.
There will be no control characters, single quote, or double quote characters. For example, source = "string s = "/* Not a comment. */";" will not be a test case. (Also, nothing else such as defines or macros will interfere with the comments.)
It is guaranteed that every open block comment will eventually be closed, so /* outside of a line or block comment always starts a new comment.
Finally, implicit newline characters can be deleted by block comments. Please see the examples below for details.
After removing the comments from the source code, return the source code in the same format.
Example 1:
Input: source = ["/*Test program */", "int main()", "{ ", " // variable declaration ", "int a, b, c;", "/* This is a test", " multiline ", " comment for ", " testing */", "a = b + c;", "}"] The line by line code is visualized as below: /*Test program */ int main() { // variable declaration int a, b, c; /* This is a test multiline comment for testing */ a = b + c; } Output: ["int main()","{ "," ","int a, b, c;","a = b + c;","}"] The line by line code is visualized as below: int main() { int a, b, c; a = b + c; } Explanation: The string/*denotes a block comment, including line 1 and lines 6-9. The string//denotes line 4 as comments.
Example 2:
Input: source = ["a/*comment", "line", "more_comment*/b"] Output: ["ab"] Explanation: The original source string is "a/*comment\nline\nmore_comment*/b", where we have bolded the newline characters. After deletion, the implicit newline characters are deleted, leaving the string "ab", which when delimited by newline characters becomes ["ab"].
Note:
The length ofsource is in the range
[1, 100].The length of
source[i] is in the range
[0, 80].Every open block comment is eventually closed.There are no single-quote, double-quote, or control characters in the source code.
题意：
这么长的题，其实本质是实现去掉C++注释的功能。基本思路是匹配字符串"//" "/*" "*/"。
其中的注意点（坑：
1. 多行注释比单行注释的优先级高，当检测到 "/*" 时，无需行注释符 "//" 判断；
2. 多行注释时要保留注释前的字符串，如例子二；
3. 单行注释也需要保留注释符号前的字符串；
4. 注释后的字符串如果长度为0，则去除这一行；
5. 在判断了 "/*" 及 "*/" 时，需要将扫描索引+1，避免在 "/*/" 等情况的时候会误判。
代码（两次AC：
vector<string> removeComments(vector<string>& source) {
vector<string> res;
string cur = "";
bool comment = false;
for(int i = 0; i<source.size(); i++)
{
for(int j = 0; j<source[i].size(); j++)
{
if(!comment && j < source[i].size() - 1 && source[i][j] == '/' && source[i][j+1] == '/')
break;
else if(!comment && j < source[i].size() - 1 && source[i][j] == '/' && source[i][j+1] == '*')
{
comment = true;
j++;
continue;
}
else if(comment && j < source[i].size() - 1 && source[i][j] == '*' && source[i][j+1] == '/')
{
comment = false;
j++;
continue;
}
else if(!comment)
cur += source[i][j];
}
if(comment || cur.length() == 0)
continue;
res.push_back(cur);
cur = "";
}
if(cur.length() > 0)
res.push_back(cur);
return res;
}题外话：
听着Taylor的Long Live，突然很热血。期许。