3

Author: kedebug

SubstringwithConcatenationofAllWords/SubstringwithConcatenationofAllWords.cpp

@@ -0,0 +1,77 @@
+class Solution {
+public:
+    // 1612ms
+    vector<int> findSubstring(string S, vector<string> &L) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        int M = L.size();
+        int N = L[0].size();
+        
+        vector<int> indices;
+        if (S.size() < M * N) return indices;
+        
+        map<string, int> words_dict;
+        for (int i = 0; i < M; i++)
+            words_dict[L[i]] += 1;
+            
+        for (int i = 0; i <= S.size() - M*N; i++) {
+            map<string, int> has_found;
+            bool flag = true;
+            for (int j = 0; j < M; j++) {
+                string sub_string = S.substr(i + j * N, N);
+                if (words_dict.find(sub_string) == words_dict.end()) {
+                    flag = false; break;
+                }
+                has_found[sub_string] += 1;
+                if (has_found[sub_string] > words_dict[sub_string]) {
+                    flag = false; break;
+                }
+            }
+            if (flag) indices.push_back(i);
+        }
+        return indices;
+    }
+};
+
+//
+// Solution2 : 1356ms
+//
+class Solution {
+public:
+    vector<int> findSubstring(string S, vector<string> &L) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        int M = L.size();
+        int N = L[0].size();
+        
+        vector<int> indices;
+        if (S.size() < M * N) return indices;
+        
+        map<string, int> words_dict;
+        for (int i = 0; i < M; i++)
+            words_dict[L[i]] += 1;
+            
+        for (int i = 0; i < N; i++) {
+            vector<string> substrings;
+            for (int j = i; j + N <= S.size(); j += N)
+                substrings.push_back(S.substr(j, N));
+            for (int j = 0; j + M <= substrings.size(); j++) {
+                map<string, int> has_found;
+                bool flag = true;
+                for (int k = 0; k < M; k++) {
+                    if (words_dict.find(substrings[j+k]) == words_dict.end()) {
+                        flag = false; break;
+                    }
+                    has_found[substrings[j+k]] += 1;
+                    if (has_found[substrings[j+k]] > words_dict[substrings[j+k]]) {
+                        flag = false; break;
+                    }
+                }
+                if (flag) indices.push_back(i + j * N);
+            }
+        }
+        return indices;
+    }
+};