feat: solve problem with cpp17

Author: HONGJICAI

cpp/30.SubstringwithConcatenationofAllWords.cpp

@@ -0,0 +1,42 @@
+class Solution {
+//Runtime: 20 ms, faster than 98.91% of C++ online submissions for Substring with Concatenation of All Words.
+//Memory Usage: 10.8 MB, less than 99.11% of C++ online submissions for Substring with Concatenation of All Words.
+public:
+    vector<int> findSubstring(string SS, vector<string> &L) {
+        vector<int> ans;
+        if (SS.size() == 0 || L.size() == 0)
+            return ans;
+        string_view S=SS;
+        unordered_map<string_view, int> dict;
+        for (const auto&s:L)
+            ++dict[s];
+        const int wl = L[0].size();
+        const int totalLength = L.size() * wl;
+        auto slideLeftWindow = [wl](auto& tdict,auto& S,auto& left,auto&count){
+            --tdict[S.substr(left, wl)];
+            --count;
+            left += wl;
+        };
+        for (int i = 0; i < wl; ++i) {
+            int left = i, count = 0;
+            unordered_map<string_view, int> tdict;
+            for (int j = i; left + totalLength <= S.size(); j += wl)
+                if (auto str = S.substr(j, wl);dict.count(str)) {
+                    ++tdict[str];
+                    ++count;
+                    if (tdict[str] <= dict[str] && count == L.size()) {
+                        ans.push_back(left);
+                        slideLeftWindow(tdict,S,left,count);
+                    }
+                    else while (tdict[str] > dict[str])
+                        slideLeftWindow(tdict,S,left,count);
+                }
+                else {
+                    tdict.clear();
+                    count = 0;
+                    left = j + wl;
+                }
+        }
+        return ans;
+    }
+};