Problems:2, 7, 14, 67, 69

Author: artakharutyunyan

1-99/14.LongestCommonPrefix.js

@@ -0,0 +1,14 @@
+var longestCommonPrefix = function (strs) {
+    if (!strs.length) return ""; 
+    
+    let prefix = strs[0];
+
+    for (let i = 1; i < strs.length; i++) {
+        while (strs[i].indexOf(prefix) !== 0) {
+            prefix = prefix.slice(0, -1);
+            if (prefix === "") return ""; 
+        }
+    }
+
+    return prefix; 
+};

1-99/2.AddTwoNumbers.js

@@ -0,0 +1,20 @@
+var addTwoNumbers = function (l1, l2) {
+  const dummyHead = new ListNode();
+  let carry = 0;
+  let currentNode = dummyHead;
+
+  while (l1 || l2 || carry) {
+    const sum = (l1?.val || 0) + (l2?.val || 0) + carry;
+
+    carry = Math.floor(sum / 10);
+
+    currentNode.next = new ListNode(sum % 10);
+
+    currentNode = currentNode.next;
+
+    l1 = l1?.next;
+    l2 = l2?.next;
+  }
+
+  return dummyHead.next;
+};

1-99/67.AddBinary.js

@@ -0,0 +1,20 @@
+var addBinary = function (a, b) {
+  let i = a.length - 1;
+  let j = b.length - 1;
+  let carry = 0;
+  let result = '';
+
+  while (i >= 0 || j >= 0 || carry) {
+    const bitA = i >= 0 ? parseInt(a[i], 10) : 0;
+    const bitB = j >= 0 ? parseInt(b[j], 10) : 0;
+
+    const sum = bitA + bitB + carry;
+    result = (sum % 2) + result;
+    carry = Math.floor(sum / 2);
+
+    i--;
+    j--;
+  }
+
+  return result;
+};

1-99/69.Sqrt(x).js

@@ -0,0 +1,22 @@
+var mySqrt = function (x) {
+  if (x === 0 || x === 1) return x;
+
+  let left = 1,
+    right = x,
+    result = 0;
+
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+
+    if (mid * mid === x) {
+      return mid;
+    } else if (mid * mid < x) {
+      result = mid;
+      left = mid + 1;
+    } else {
+      right = mid - 1;
+    }
+  }
+
+  return result;
+};

1-99/7.ReverseInteger.js

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+var reverse = function (x) {
+  const INT_MIN = -(2 ** 31);
+  const INT_MAX = 2 ** 31 - 1;
+
+  let result = 0;
+
+  while (x !== 0) {
+    const digit = x % 10;
+    x = (x / 10) | 0;
+
+    if (
+      result > Math.floor(INT_MAX / 10) ||
+      (result === Math.floor(INT_MAX / 10) && digit > 7)
+    ) {
+      return 0;
+    }
+    if (
+      result < Math.ceil(INT_MIN / 10) ||
+      (result === Math.ceil(INT_MIN / 10) && digit < -8)
+    ) {
+      return 0;
+    }
+
+    result = result * 10 + digit;
+  }
+
+  return result;
+};