#include #include // count_if #include using namespace std; void string_algorithm() { string s1 = "variety is the spice of life."; string s2 = "Pang pang pang pang."; int num = count(s1.begin(), s1.end(), 'e'); // 4 (total 4 'e') num = count_if(s1.begin(), s1.end(), [](char c) { return (c <= 'e' && c >= 'a');});// lambda expression, result 6 (total contain a b c d e) s1 = "Goodness is a successful lady."; string::iterator itr = search_n(s1.begin(), s1.begin()+2,2,'s' ); // seaching syllable 'ss', itr -> first s s1.erase(itr, itr + 5); // remove from itr at size 5 so "ss is" removed s1.insert(itr, 3, 'x'); // insert 3 x at itr //s1.replace(itr, itr + 1, 'y'); // replace substring ,3 char start from itr // algorithm is_permutation(s1.begin(), s1.end(), s2.begin()); replace(s1.begin(), s1.end(), 'e', ' '); // replace all char e to space transform(s1.begin(), s1.end(), s2.begin(), [](char c) { if (c < 'n') return 'a'; else return 'z'; }); // save result to s2 s1 = "abcdefg"; rotate(s1.begin(), s1.begin() + 3, s1.end()); // defgabc: rotate at pos@3 u16string s3; // string char16_t u32string s4; // string char32_t wstring s5; // string wchar_t, wide character } int main() { }