add solutions

Author: temanisparsh

problems/1356.json

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+{"link": "https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits", "name": "Sort Integers by The Number of 1 Bits", "difficulty": "Easy", "statement": "<div><p>Given an integer array <code>arr</code>. You have to sort the integers in the array&nbsp;in ascending order by the number of <strong>1's</strong>&nbsp;in their binary representation and in case of two or more integers have the same number of <strong>1's</strong> you have to sort them in ascending order.</p>\n\n<p>Return <em>the sorted array</em>.</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n\n<pre><strong>Input:</strong> arr = [0,1,2,3,4,5,6,7,8]\n<strong>Output:</strong> [0,1,2,4,8,3,5,6,7]\n<strong>Explantion:</strong> [0] is the only integer with 0 bits.\n[1,2,4,8] all have 1 bit.\n[3,5,6] have 2 bits.\n[7] has 3 bits.\nThe sorted array by bits is [0,1,2,4,8,3,5,6,7]\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre><strong>Input:</strong> arr = [1024,512,256,128,64,32,16,8,4,2,1]\n<strong>Output:</strong> [1,2,4,8,16,32,64,128,256,512,1024]\n<strong>Explantion:</strong> All integers have 1 bit in the binary representation, you should just sort them in ascending order.\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre><strong>Input:</strong> arr = [10000,10000]\n<strong>Output:</strong> [10000,10000]\n</pre>\n\n<p><strong>Example 4:</strong></p>\n\n<pre><strong>Input:</strong> arr = [2,3,5,7,11,13,17,19]\n<strong>Output:</strong> [2,3,5,17,7,11,13,19]\n</pre>\n\n<p><strong>Example 5:</strong></p>\n\n<pre><strong>Input:</strong> arr = [10,100,1000,10000]\n<strong>Output:</strong> [10,100,10000,1000]\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 &lt;= arr.length &lt;= 500</code></li>\n\t<li><code>0 &lt;= arr[i] &lt;= 10^4</code></li>\n</ul>\n</div>", "language": "cpp", "solution": "#include <iostream>\n#include <bits/stdc++.h>\n\nusing namespace std;\n\nint one_count(int a) {\n    if (a == 0) return 0;\n    return a % 2 + one_count(a / 2);\n}\n\nbool comp(int a, int b)\n{\n    int c = one_count(a);\n    int d = one_count(b);\n    if (c == d) {\n        return a < b;\n    }\n    return c < d;\n}\n\nclass Solution\n{\npublic:\n    vector<int> sortByBits(vector<int> &arr)\n    {\n        sort(arr.begin(), arr.end());\n        sort(arr.begin(), arr.end(), comp);\n        return arr;\n    }\n};"}

problems/1491.json

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+{"link": "https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary", "name": "Average Salary Excluding the Minimum and Maximum Salary", "difficulty": "Easy", "statement": "<div><p>Given an array of <strong>unique</strong> integers <code>salary</code>&nbsp;where <code>salary[i]</code> is the salary of the employee <code>i</code>.</p>\n\n<p>Return the average salary of employees excluding the minimum and maximum salary.</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n\n<pre><strong>Input:</strong> salary = [4000,3000,1000,2000]\n<strong>Output:</strong> 2500.00000\n<strong>Explanation: </strong>Minimum salary and maximum salary are 1000 and 4000 respectively.\nAverage salary excluding minimum and maximum salary is (2000+3000)/2= 2500\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre><strong>Input:</strong> salary = [1000,2000,3000]\n<strong>Output:</strong> 2000.00000\n<strong>Explanation: </strong>Minimum salary and maximum salary are 1000 and 3000 respectively.\nAverage salary excluding minimum and maximum salary is (2000)/1= 2000\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre><strong>Input:</strong> salary = [6000,5000,4000,3000,2000,1000]\n<strong>Output:</strong> 3500.00000\n</pre>\n\n<p><strong>Example 4:</strong></p>\n\n<pre><strong>Input:</strong> salary = [8000,9000,2000,3000,6000,1000]\n<strong>Output:</strong> 4750.00000\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>3 &lt;= salary.length &lt;= 100</code></li>\n\t<li><code>10^3&nbsp;&lt;= salary[i] &lt;= 10^6</code></li>\n\t<li><code>salary[i]</code> is unique.</li>\n\t<li>Answers within <code>10^-5</code> of the actual value will be accepted as correct.</li>\n</ul></div>", "language": "cpp", "solution": "#include <iostream>\n#include <bits/stdc++.h>\n\nusing namespace std;\n\nclass Solution\n{\npublic:\n    double average(vector<int> &salary)\n    {\n        sort(salary.begin(), salary.end());\n        int n = salary.size();\n        int sum = 0;\n        for (double i : salary)\n            sum += i;\n        sum -= salary[0];\n        sum -= salary[n - 1];\n\n        return (double)(sum / (double)(n - 2));\n    }\n};"}

problems/344.json

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+{"link": "https://leetcode.com/problems/reverse-string", "name": "Reverse String", "difficulty": "Easy", "statement": "<div><p>Write a function that reverses a string. The input string is given as an array of characters <code>char[]</code>.</p>\n\n<p>Do not allocate extra space for another array, you must do this by <strong>modifying the input array&nbsp;<a href=\"https://en.wikipedia.org/wiki/In-place_algorithm\" target=\"_blank\">in-place</a></strong> with O(1) extra memory.</p>\n\n<p>You may assume all the characters consist of <a href=\"https://en.wikipedia.org/wiki/ASCII#Printable_characters\" target=\"_blank\">printable ascii characters</a>.</p>\n\n<p>&nbsp;</p>\n\n<div>\n<p><strong>Example 1:</strong></p>\n\n<pre><strong>Input: </strong><span id=\"example-input-1-1\">[\"h\",\"e\",\"l\",\"l\",\"o\"]</span>\n<strong>Output: </strong><span id=\"example-output-1\">[\"o\",\"l\",\"l\",\"e\",\"h\"]</span>\n</pre>\n\n<div>\n<p><strong>Example 2:</strong></p>\n\n<pre><strong>Input: </strong><span id=\"example-input-2-1\">[\"H\",\"a\",\"n\",\"n\",\"a\",\"h\"]</span>\n<strong>Output: </strong><span id=\"example-output-2\">[\"h\",\"a\",\"n\",\"n\",\"a\",\"H\"]</span>\n</pre>\n</div>\n</div>\n</div>", "language": "cpp", "solution": "#include <iostream>\n#include <bits/stdc++.h>\n\nusing namespace std;\n\nclass Solution\n{\npublic:\n    void reverseString(vector<char> &s)\n    {\n        int n = s.size();\n        for(int i = 0; i < n / 2; i++) {\n            int temp = s[i];\n            s[i] = s[n - i - 1];\n            s[n - i - 1] = temp;\n        }\n    }\n};"}

problems/559.json

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+{"link": "https://leetcode.com/problems/maximum-depth-of-n-ary-tree", "name": "Maximum Depth of N-ary Tree", "difficulty": "Easy", "statement": "<div><p>Given a n-ary tree, find its maximum depth.</p>\n\n<p>The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.</p>\n\n<p><em>Nary-Tree input serialization&nbsp;is represented in their level order traversal, each group of children is separated by the null value (See examples).</em></p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n\n<p><img src=\"https://assets.leetcode.com/uploads/2018/10/12/narytreeexample.png\" style=\"width: 100%; max-width: 300px;\"></p>\n\n<pre><strong>Input:</strong> root = [1,null,3,2,4,null,5,6]\n<strong>Output:</strong> 3\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<p><img alt=\"\" src=\"https://assets.leetcode.com/uploads/2019/11/08/sample_4_964.png\" style=\"width: 296px; height: 241px;\"></p>\n\n<pre><strong>Input:</strong> root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n<strong>Output:</strong> 5\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li>The depth of the n-ary tree is less than or equal to <code>1000</code>.</li>\n\t<li>The total number of nodes is between <code>[0,&nbsp;10^4]</code>.</li>\n</ul>\n</div>", "language": "c", "solution": "\nstruct Node\n{\n    int val;\n    int numChildren;\n    struct Node **children;\n};\n\nint *maxDepth(struct Node *root)\n{\n    return calc_depth(root, 0);\n}\n\nint calc_depth(struct Node *root, int depth)\n{\n    if (!root)\n        return depth;\n    int old_depth = depth;\n    depth += 1;\n    for (int i = 0; i < root->numChildren; i++)\n    {\n        int newd = calc_depth(root->children[i], old_depth + 1);\n        printf(\"%d\\n\", newd);\n        depth = depth > newd ? depth : newd;\n    }\n    return depth;\n}"}

problems/876.json

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+{"link": "https://leetcode.com/problems/middle-of-the-linked-list", "name": "Middle of the Linked List", "difficulty": "Easy", "statement": "<div><p>Given a non-empty, singly&nbsp;linked list with head node <code>head</code>, return&nbsp;a&nbsp;middle node of linked list.</p>\n\n<p>If there are two middle nodes, return the second middle node.</p>\n\n<p>&nbsp;</p>\n\n<div>\n<p><strong>Example 1:</strong></p>\n\n<pre><strong>Input: </strong><span id=\"example-input-1-1\">[1,2,3,4,5]</span>\n<strong>Output: </strong>Node 3 from this list (Serialization: <span id=\"example-output-1\">[3,4,5]</span>)\nThe returned node has value 3.  (The judge's serialization of this node is [3,4,5]).\nNote that we returned a ListNode object ans, such that:\nans.val = 3, ans.next.val = 4, ans.next.next.val = 5, and ans.next.next.next = NULL.\n</pre>\n\n<div>\n<p><strong>Example 2:</strong></p>\n\n<pre><strong>Input: </strong><span id=\"example-input-2-1\">[1,2,3,4,5,6]</span>\n<strong>Output: </strong>Node 4 from this list (Serialization: <span id=\"example-output-2\">[4,5,6]</span>)\nSince the list has two middle nodes with values 3 and 4, we return the second one.\n</pre>\n\n<p>&nbsp;</p>\n\n<p><strong>Note:</strong></p>\n\n<ul>\n\t<li>The number of nodes in the given list will be between <code>1</code>&nbsp;and <code>100</code>.</li>\n</ul>\n</div>\n</div>\n</div>", "language": "C", "solution": "\nstruct ListNode\n{\n    int val;\n    struct ListNode *next;\n};\n\nstruct ListNode *middleNode(struct ListNode *head)\n{\n    int n = 0;\n    struct ListNode* curr = head;\n\n    while(curr) {\n        curr = curr->next;\n        ++n;\n    }\n    curr = head;\n    for(int i = 0;  i < n/2; ++i)\n        curr = curr->next;\n    return curr;\n}"}

solutions/easy/1356.cpp

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+#include <iostream>
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int one_count(int a) {
+    if (a == 0) return 0;
+    return a % 2 + one_count(a / 2);
+}
+
+bool comp(int a, int b)
+{
+    int c = one_count(a);
+    int d = one_count(b);
+    if (c == d) {
+        return a < b;
+    }
+    return c < d;
+}
+
+class Solution
+{
+public:
+    vector<int> sortByBits(vector<int> &arr)
+    {
+        sort(arr.begin(), arr.end());
+        sort(arr.begin(), arr.end(), comp);
+        return arr;
+    }
+};

solutions/easy/1491.cpp

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+#include <iostream>
+#include <bits/stdc++.h>
+
+using namespace std;
+
+class Solution
+{
+public:
+    double average(vector<int> &salary)
+    {
+        sort(salary.begin(), salary.end());
+        int n = salary.size();
+        int sum = 0;
+        for (double i : salary)
+            sum += i;
+        sum -= salary[0];
+        sum -= salary[n - 1];
+
+        return (double)(sum / (double)(n - 2));
+    }
+};

solutions/easy/344.cpp

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+#include <iostream>
+#include <bits/stdc++.h>
+
+using namespace std;
+
+class Solution
+{
+public:
+    void reverseString(vector<char> &s)
+    {
+        int n = s.size();
+        for(int i = 0; i < n / 2; i++) {
+            int temp = s[i];
+            s[i] = s[n - i - 1];
+            s[n - i - 1] = temp;
+        }
+    }
+};

solutions/easy/559.c

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+
+struct Node
+{
+    int val;
+    int numChildren;
+    struct Node **children;
+};
+
+int *maxDepth(struct Node *root)
+{
+    return calc_depth(root, 0);
+}
+
+int calc_depth(struct Node *root, int depth)
+{
+    if (!root)
+        return depth;
+    int old_depth = depth;
+    depth += 1;
+    for (int i = 0; i < root->numChildren; i++)
+    {
+        int newd = calc_depth(root->children[i], old_depth + 1);
+        printf("%d\n", newd);
+        depth = depth > newd ? depth : newd;
+    }
+    return depth;
+}

solutions/easy/876.C

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+
+struct ListNode
+{
+    int val;
+    struct ListNode *next;
+};
+
+struct ListNode *middleNode(struct ListNode *head)
+{
+    int n = 0;
+    struct ListNode* curr = head;
+
+    while(curr) {
+        curr = curr->next;
+        ++n;
+    }
+    curr = head;
+    for(int i = 0;  i < n/2; ++i)
+        curr = curr->next;
+    return curr;
+}