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トップC++に関する質問string空白ありで何個目かの文字列を取り出す

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4

追記

2018/02/11 11:26

投稿

episteme
episteme

スコア16614

test CHANGED
@@ -101,3 +101,75 @@
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  */
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  ```
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+
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+ [追記] こっち↓の方がツブシが利くかなー...
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+
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+ ```C++
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+
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+ template<typename String,typename Function>
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+
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+ void tokenize(const String& str, const String& delim, Function&& fun) {
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+
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+ for ( typename String::size_type spos, epos = 0;
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+
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+ (spos = str.find_first_not_of(delim, epos)) != String::npos;) {
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+
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+ fun(str.substr(spos,(epos = str.find_first_of(delim, spos))-spos));
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+
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+ }
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+
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+ }
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+
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+
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+
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+ /* おためし */
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+
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+ #include <iostream>
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+
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+ #include <string>
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+
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+
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+
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+ int main() {
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+
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+ using namespace std;
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+
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+ string input[] = {
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+
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+ "abc",
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+
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+ "a bb ccc",
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+
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+ " a bb ccc",
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+
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+ "a bb ccc ",
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+
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+ " a bb ccc dddd ",
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+
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+ " ",
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+
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+ ""
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+
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+ };
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+
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+ for ( const auto& item : input ) {
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+
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+ using namespace std::literals::string_literals;
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+
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+ cout << '[' << item << "] -> \n ";
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+
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+ int count = 0;
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+
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+ auto print = [&](const string& token) { cout << ++count << '[' << token << "] ";};
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+
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+ tokenize(item, " "s, print);
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+
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+ cout << endl;
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+
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+ }
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+
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+
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+
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+ }
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+
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+ ```

3

修正

2018/02/11 11:26

投稿

episteme
episteme

スコア16614

test CHANGED
@@ -8,13 +8,13 @@
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8
 
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- template<typename OutputIterator>
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+ template<typename String,typename OutputIterator>
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- OutputIterator tokenize(const std::string& str, const std::string& delim, OutputIterator out) {
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+ OutputIterator tokenize(const String& str, const String& delim, OutputIterator out) {
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- std::string::size_type spos, epos = 0;
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+ for ( typename String::size_type spos, epos = 0;
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- while ( (spos = str.find_first_not_of(delim, epos)) != std::string::npos ) {
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+ (spos = str.find_first_not_of(delim, epos)) != String::npos;) {
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  *out++ = str.substr(spos,(epos = str.find_first_of(delim, spos))-spos);
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@@ -38,6 +38,8 @@
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  using namespace std;
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+
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+
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  vector<string> input = {
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  "abc",
@@ -56,15 +58,15 @@
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  };
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- vector<string> out;
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+ for ( const auto& item : input ) {
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- for ( const string item : input ) {
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+ using namespace std::literals::string_literals;
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  cout << '[' << item << "] -> ";
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- out.clear();
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+ vector<string> out;
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- tokenize(item, " ", back_inserter(out));
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+ tokenize(item, " "s, back_inserter(out));
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  for ( const auto& token : out ) {
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2

修正

2018/02/11 10:01

投稿

episteme
episteme

スコア16614

test CHANGED
@@ -12,15 +12,11 @@
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  OutputIterator tokenize(const std::string& str, const std::string& delim, OutputIterator out) {
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- std::string::size_type pos = 0;
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+ std::string::size_type spos, epos = 0;
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- std::string::size_type len = 0;
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+ while ( (spos = str.find_first_not_of(delim, epos)) != std::string::npos ) {
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- while ( (pos = str.find_first_not_of(delim, pos+len)) != std::string::npos ) {
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-
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- len = str.find_first_of(delim, pos) - pos;
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+ *out++ = str.substr(spos,(epos = str.find_first_of(delim, spos))-spos);
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-
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- *out++ = str.substr(pos,len);
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  }
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22
 

1

修正

2018/02/11 09:50

投稿

episteme
episteme

スコア16614

test CHANGED
@@ -12,23 +12,15 @@
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  OutputIterator tokenize(const std::string& str, const std::string& delim, OutputIterator out) {
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- typedef std::pair<std::string::size_type, std::string::size_type> result_type;
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-
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  std::string::size_type pos = 0;
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- std::string::size_type len;
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+ std::string::size_type len = 0;
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- while ( true ) {
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-
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- pos = str.find_first_not_of(delim, pos);
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+ while ( (pos = str.find_first_not_of(delim, pos+len)) != std::string::npos ) {
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-
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- if ( pos == std::string::npos ) break;
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  len = str.find_first_of(delim, pos) - pos;
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  *out++ = str.substr(pos,len);
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-
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- pos += len;
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  }
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