adamkorg

#include <iostream>
#include <vector>
#include <queue>

using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;

adamkorg

#include <iostream>
#include <string>
#include <vector>
#include <sstream> 
#include <iomanip>

using namespace std;

static const int hexStrLen() { return sizeof(int)*2; }

adamkorg

#include <iostream>
#include <cmath>

using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}

adamkorg

#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
#include <unordered_set>
#include <queue>

using namespace std;

typedef unordered_map<char, unordered_set<char>> GraphMap;

adamkorg

#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

int missingNumber(vector<int>& nums) {
    int len=nums.size();
    int res = (len*(len+1))/2;
    for (int val : nums) res -= val;

adamkorg

#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

int missingNumber(vector<int>& nums) {
    int num=nums.size();
    for (int i=0; i<nums.size(); ++i) 
        num ^= (i ^ nums[i]);

adamkorg

#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

int missingNumber(vector<int>& nums) {
    int xorAll=0, xorMissing=0, len=nums.size();
    for (int i=0; i<len; ++i) xorMissing ^= nums[i];
    for (int i=0; i<len+1; ++i) xorAll ^= i;

adamkorg

#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

int missingNumber(vector<int>& nums) {
    unordered_set<int> s;
    for (int n : nums) s.insert(n);
    for (int i=0; i<=nums.size(); ++i) {

adamkorg

#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>

using namespace std;

void combinations(string& letters, string& comb, bool odd, char oddch, vector<string>& res) {
    if (letters.size() == 0) {
        string rev = comb;

adamkorg

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

bool canPermutePalindrome(string s) {
    unordered_map<char, int> m;
    bool odd = (s.size() %2 != 0);
    int countOdd=0;