Create Word_Break_II.cc

Author: iphkwan

Word_Break_II.cc

@@ -0,0 +1,40 @@
+class Solution {
+public:
+    vector<string> wordBreak(string s, unordered_set<string> &dict) {
+        // Note: The Solution object is instantiated only once and is reused by each test case.
+        if (s == "")
+            return vector<string>();
+        dp.assign(s.length() + 1, vector<int>());
+        dp[0].push_back(-1);
+        for (int i = 0; i < s.length(); i++) {
+            if (dp[i].size() == 0)
+                continue;
+            for (int j = 1; i + j <= s.length(); j++) {
+                if (dict.find(s.substr(i, j)) != dict.end()) {
+                    dp[i + j].push_back(i);
+                }
+            }
+        }
+        
+        vector<string> ret;
+        string tmp = "";
+        
+        dfs(ret, tmp, s, s.length());
+        return ret;
+    }
+private:
+    vector< vector<int> > dp;
+    void dfs(vector<string> &ret, string tmp, string &s, int cur) {
+        if (cur == 0) {
+            ret.push_back(tmp);
+            return;
+        }
+        for (int i = 0; i < dp[cur].size(); i++) {
+            if (cur == s.length()) {
+                dfs(ret, s.substr(dp[cur][i], cur - dp[cur][i]), s, dp[cur][i]);
+            } else {
+                dfs(ret, s.substr(dp[cur][i], cur - dp[cur][i]) + " " + tmp, s, dp[cur][i]);
+            }
+        }
+    }
+};