leetcode Word Break II

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Give two versions of WA code:

Version 1: Runtime Error: Find the bug

class Solution { public:  void find(const string& s, const unordered_set<string>& dict, vector<int>& res) {    int i, j, len = s.length();    for (i = 0; i < len; ++i) {      if (dict.find(s.substr(0, i + 1)) != dict.end()) {        res.push_back(i);      }    }  }  void addSpace(vector<string>& cur, vector<vector<string> >& resvec,                 const string& s, const unordered_set<string>& dict) {    if (s.length() == 0) {      resvec.push_back(cur);      return;    }    vector<int> breakpoints;    find(s, dict, breakpoints);    for (int i = 0; i < breakpoints.size(); ++i) {      cur.push_back(s.substr(0, breakpoints[i] + 1));      addSpace(cur, resvec, s.substr(breakpoints[i]), dict);      cur.pop_back();    }  }  vector<string> wordBreak(string s, unordered_set<string> &dict) {    int i, j, size;    vector<vector<string> > resvec;    vector<string> res, cur;        addSpace(cur, resvec, s, dict);    for (i = 0; i < resvec.size(); ++i) {      string tmp = resvec[i][0];      for (j = 1; j < resvec[i].size(); ++j)         tmp += " " + resvec[i][j];      res.push_back(tmp);    }    return res;  }};

Version 2: TLE

class Solution { public:  void find(const string& s, const unordered_set<string>& dict, vector<int>& res) {    int i, j, len = s.length();    for (i = 0; i < len; ++i) {      if (dict.find(s.substr(0, i + 1)) != dict.end()) {        res.push_back(i);      }    }  }  void addSpace(vector<string>& cur, vector<vector<string> >& resvec,                 const string& s, const unordered_set<string>& dict) {    if (s.length() == 0) {      resvec.push_back(cur);      return;    }    vector<int> breakpoints;    find(s, dict, breakpoints);    for (int i = 0; i < breakpoints.size(); ++i) {      cur.push_back(s.substr(0, breakpoints[i] + 1));      addSpace(cur, resvec, s.substr(breakpoints[i] + 1), dict);      cur.pop_back();    }  }  vector<string> wordBreak(string s, unordered_set<string> &dict) {    int i, j, size;    vector<vector<string> > resvec;    vector<string> res, cur;        addSpace(cur, resvec, s, dict);    for (i = 0; i < resvec.size(); ++i) {      string tmp = resvec[i][0];      for (j = 1; j < resvec[i].size(); ++j)         tmp += " " + resvec[i][j];      res.push_back(tmp);    }    return res;  }};

Version 3: AC Code:

class Solution { public:  void find(const string& s, const unordered_set<string>& dict, vector<int>& res) {    int i, j, len = s.length();    for (i = 0; i < len; ++i) {      if (dict.find(s.substr(0, i + 1)) != dict.end()) {        res.push_back(i);      }    }  }  void addSpace(vector<string>& cur, vector<vector<string> >& resvec,                 const string& s, const unordered_set<string>& dict, vector<int>& forbidden) {        if (s.length() == 0) {      resvec.push_back(cur);      return;    }    if (forbidden[s.length()])      return;    vector<int> breakpoints;    find(s, dict, breakpoints);    for (int i = 0; i < breakpoints.size(); ++i) {      cur.push_back(s.substr(0, breakpoints[i] + 1));      int resvecsize = resvec.size();      addSpace(cur, resvec, s.substr(breakpoints[i] + 1), dict, forbidden);      if (resvec.size() == resvecsize)        forbidden[s.length()-breakpoints[i]-1] = 1;      cur.pop_back();    }  }  vector<string> wordBreak(string s, unordered_set<string> &dict) {    int i, j, size;    vector<vector<string> > resvec;    vector<string> res, cur;    vector<int> forbidden(s.length()+1, 0);        addSpace(cur, resvec, s, dict, forbidden);    for (i = 0; i < resvec.size(); ++i) {      string tmp = resvec[i][0];      for (j = 1; j < resvec[i].size(); ++j)         tmp += " " + resvec[i][j];      res.push_back(tmp);    }    return res;  }};

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