给你三个string str oldstr newstr 用newstr替换str里的oldstr

#include<iostream>   #include<string>  #include<vector>   using namespace std;/*void func(string &s, string &oldVal,const string &newVal){string::size_type size = oldVal.size();for (string::size_type i = 0;i<s.length()-size; i++){if (s.substr(i,size)==oldVal){s.replace(i, size, newVal);}}}*/void func1(string &s, string &oldValue, string &newValue){int _size = oldValue.size();string::iterator it1 = s.begin();string::iterator it2 = newValue.begin();string::iterator it3 = newValue.begin();for (it1; it1 <= (s.end() - oldValue.size() + 1); ++it1){it1 = s.erase(it1, it1 + _size);//返回的是最后一个被会删除的元素之后的位置s.insert(it1, it2, it3);//原因在于insert（）函数返回}}void func(string &s, string &oldValue, string &newValue){int _size = oldValue.size();string::iterator it1 = s.begin();string::iterator it2 = newValue.begin();string::iterator it3 = newValue.end();for (; it1 <= (s.end() - _size + 1); ++it1){if ((s.substr(it1 - s.begin(), _size) == oldValue)){it1 = s.erase(it1, it1 + _size);it1 = s.insert(it1, it2, it3);//advance(it1, _size);it1 += _size;}}}int main(int argc, char**argv){string s = "2134bbaaaaabbaaa";string oldval = "bb";string newval = "kkk";func(s, oldval, newval);cout << s << endl;system("pause");return 0;}