6 problems solved.

lintcoder · lintcoder · commit 41f8c438576a · 2021-02-13T19:25:22.000+08:00
diff --git a/src/1561.cpp b/src/1561.cpp
@@ -0,0 +1,15 @@
+int maxCoins(vector<int>& piles) {
+        int len = piles.size();
+        sort(piles.begin(), piles.end());
+        int sum = 0;
+        int lim = len/3;
+        int i = len-2;
+        while (i >= 0 && lim > 0)
+        {
+            sum += piles[i];
+            i -= 2;
+            --lim;
+        }
+        
+        return sum;
+    }
diff --git a/src/1641.cpp b/src/1641.cpp
@@ -0,0 +1,18 @@
+int countVowelStrings(int n) {
+        int ct = 0;
+        for (int i = 0; i < 5; ++i)
+            dfs(0, i, n, ct);
+        
+        return ct;
+    }
+    
+    void dfs(int index, int v, int n, int& ct)
+    {
+        if (index == n-1)
+            ++ct;
+        else
+        {
+            for (int i = v; i < 5; ++i)
+                dfs(index+1, i, n, ct);
+        }
+    }
diff --git a/src/1669.cpp b/src/1669.cpp
@@ -0,0 +1,25 @@
+ListNode* mergeInBetween(ListNode* list1, int a, int b, ListNode* list2) {
+        ListNode* p = list1, *q = list2;
+        ListNode* pr = list1;
+        int i = 0;
+        while (i < a-1)
+        {
+            p = p->next;
+            pr = p;
+            ++i;
+        }
+        while (i < b)
+        {
+            pr = pr->next;
+            ++i;
+        }
+        
+        while (q->next != nullptr)
+            q = q->next;
+        
+        p->next = list2;
+        q->next = pr->next;
+        pr->next = nullptr;
+        
+        return list1;
+    }
diff --git a/src/1689.cpp b/src/1689.cpp
@@ -0,0 +1,11 @@
+int minPartitions(string n) {
+        int len = n.size();
+        char c = '0';
+        for (int i = 0; i < len; ++i)
+        {
+            if (n[i] > c)
+                c = n[i];
+        }
+        
+        return c-'0';
+    }
diff --git a/src/1721.cpp b/src/1721.cpp
@@ -0,0 +1,34 @@
+ListNode* swapNodes(ListNode* head, int k) {
+        int ct = 0;
+        ListNode* p = head;
+        while (p != nullptr)
+        {
+            p = p->next;
+            ++ct;
+        }
+        
+        int i = 0, j = ct - k + 1;
+        int m = 0;
+        if (k == j)
+            return head;
+        
+        p = head;
+        ListNode* nodearr[2];
+        while (p != nullptr)
+        {
+            ++i;
+            if (i == k || i == j)
+            {
+                nodearr[m++] = p;
+                if (m == 2)
+                    break;
+            }
+            p = p->next;
+        }
+        
+        int tmp = nodearr[0]->val;
+        nodearr[0]->val = nodearr[1]->val;
+        nodearr[1]->val = tmp;
+        
+        return head;
+    }
diff --git a/src/890.cpp b/src/890.cpp
@@ -0,0 +1,38 @@
+vector<string> findAndReplacePattern(vector<string>& words, string pattern) {
+        int len = pattern.size();
+        map<char, vector<int>> mp;
+        for (int i = 0; i < len; ++i)
+        {
+            mp[pattern[i]].push_back(i);
+        }
+        
+        int sz = words.size();
+        vector<string> res;
+        for (int i = 0; i < sz; ++i)
+        {
+            int flag[26] = {0};
+            auto last = mp.end();
+            auto iter = mp.begin();
+            for (; iter != last; ++iter)
+            {
+                vector<int>& vec = iter->second;
+                int n = vec.size();
+                if (flag[words[i][vec[0]]-'a']== 1)
+                    break;
+                int j = 1;
+                for (j = 1; j < n; ++j)
+                {
+                    if (words[i][vec[0]] != words[i][vec[j]])
+                        break;
+                }
+                if (j != n)
+                    break;
+                flag[words[i][vec[0]]-'a'] = 1;
+            }
+            
+            if (iter == last)
+                res.push_back(words[i]);
+        }
+        
+        return res;
+    }
