vector<string> wordBreak(string s, unordered_set<string>& wordDict) {
const int n = s.length();
size_t max_len = 0;
for (const auto& str: wordDict) {
max_len = max(max_len, str.length());
}
vector<bool> canBreak(n + 1, false);
vector<vector<bool>> valid(n, vector<bool>(n, false));
canBreak[0] = true;
for (int i = 1; i <= n; ++i) {
for (int l = 1; l <= max_len && i - l >= 0; ++l) {
if (canBreak[i - l] && wordDict.count(s.substr(i - l, l))) {
valid[i - l][i - 1] = true;
canBreak[i] = true;
}
}
}
vector<string> result, path;
if (canBreak[n]) {
wordBreakHelper(s, valid, 0, &path, &result);
}
return result;
}
vector<string> WordBreakII::wordBreak(string s, unordered_set<string> &wordDict) {
vector<string> result;
vector<string> cur;
vector<bool> canBreak(s.size() + 1, true);
backtrack(s, wordDict, 0, cur, canBreak, result);
return result;
}
bool wordBreak(string s, unordered_set<string>& wordDict) {
const int n = s.length();
size_t max_len = 0;
for (const auto& str: wordDict) {
max_len = max(max_len, str.length());
}
vector<bool> canBreak(n + 1, false);
canBreak[0] = true;
for (int i = 1; i <= n; ++i) {
for (int l = 1; l <= max_len && i - l >= 0; ++l) {
if (canBreak[i - l] && wordDict.count(s.substr(i - l, l))) {
canBreak[i] = true;
break;
}
}
}
return canBreak[n];
}
vector<string> wordBreak(string s, unordered_set<string>& wordDict) {
vector<string> result;
string ret = "";
if (s == "") {
return result;
}
//use dp to pruning
int len = s.length();
vector<bool> canBreak(len + 1, false);
canBreak[0] = true;
for (int i = 0; i < len; i ++) {
for (int j = i; j >= 0; j --) {
if (wordDict.count(s.substr(j, i - j + 1)) && canBreak[j]) {
canBreak[i + 1] = true;
break;
}
}
}
if (!canBreak[len]) {
return result;
}
dfs(ret, 0, s, result, wordDict);
return result;
}
