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; } };
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; } };
leetcode Word Break II,布布扣,bubuko.com
原文:http://blog.csdn.net/taoqick/article/details/38357329