some leetcode problems

leetcode_problemset/problemsets/longestValidParentheses.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int longestValidParenthesis(string s) {
+    stack<int> st;
+    st.push(-1);
+    int maxCount = 0;
+
+    for(int i = 0; i < s.length(); ++i) {
+        if(s[i]=='(')
+            st.push(i);
+        else
+            st.pop();
+
+        if(st.empty())
+            st.push(i);
+        else 
+            maxCount = max(maxCount, i - st.top());
+
+    }
+
+    return maxCount;
+}

leetcode_problemset/problemsets/palindromeNumber.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef long long ll;
+
+bool isPalindrome(int x) {
+
+    if(x < 0)
+        return false;
+
+    ll ans = 0;
+    int aux = x;
+    while(x) {
+        ans = (10*ans)+(x%10);
+        x /= 10;
+    }
+
+    if(ans > INT_MAX or ans < INT_MIN) return false;
+    if(aux == ans) return true;
+
+    return false;
+
+}

leetcode_problemset/problemsets/relativeSortArray.cpp

@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+vector<int> relativeSortArray(vector<int> &arr1, vector<int> &arr2) {
+    vector<int> sorted;
+    int n = arr1.size(), m = arr2.size();
+    sort(arr1.begin(), arr1.end());
+    for(int i = 0, j = 0; i < m; ++i) {
+        for(int j = 0; j < n; ++j) {
+            if(arr1[j] == arr2[i]) {
+                sorted.emplace_back(arr1[j]);
+                arr1[j] = -1;
+            }
+        }
+    }
+
+    for(int i = 0; i < n; ++i)
+        if(arr1[i] != -1)
+            sorted.emplace_back(arr1[i]);
+
+    return sorted;
+}

leetcode_problemset/problemsets/removeDuplicates.cpp

@@ -0,0 +1,15 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int removeDuplicates(vector<int> &nums) {
+    set<int> s;
+    int size = nums.size();
+    for(int i = 0; i < size; ++i)
+        s.insert(nums[i]);
+
+    int i = 0;
+    for(auto x : s)
+        nums[i++] = x;
+
+    return s.size();
+}

leetcode_problemset/problemsets/reverseInteger.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef long long ll;
+
+int reverse(int x) {
+    ll ans = 0;
+    while (x)
+    {
+        ans = (ans * 10) + (x % 10);
+        x /= 10;
+    }
+
+    if (ans > INT_MAX or ans < INT_MIN)
+        return 0;
+    return ans;
+}
+
+int main() {
+    int value;
+    cin >> value;
+    cout << reverse(value) << endl;
+
+    return 0;
+}

leetcode_problemset/problemsets/stringToInteger.cpp

@@ -0,0 +1,18 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int myAtoi(string s) {
+
+    int ans = 0, size = s.length();
+
+    // checking if is readable
+    for(int i = 0; i < size; ++i)
+        if(isalpha(s[i]) and isalpha(s[i+1]))
+            return 0;
+
+    for(int i = 0; i < size; ++i)
+        if(isdigit(s[i]))
+            ans = ans*10+(s[i]-'0');
+
+    return s[0]==-1?-ans:ans;
+}