first-two-problems

Author: Carlysson Oliveira

longest-prefix.js

@@ -0,0 +1,37 @@
+/**
+ * @param {string[]} strs
+ * @return {string}
+ */
+var longestCommonPrefix = function (strs) {
+  var hasPrefix = true;
+  var commonIndex = 0;
+  var commonPrefix = "";
+  var index = 0;
+
+  while (hasPrefix) {
+    hasPrefix = strs[index].startsWith(commonPrefix);
+
+    if (index === strs.length - 1) {
+      if (hasPrefix) {
+        commonPrefix = commonPrefix + (strs[0][commonIndex] || "");
+
+        if (commonPrefix == "") {
+          return "";
+        }
+
+        if (commonIndex === strs[0].length) {
+          return commonPrefix;
+        }
+
+        // Increment common index to check next character
+        commonIndex++;
+        // Reset index to initial point of list
+        index = 0;
+      }
+    } else {
+      index++;
+    }
+  }
+
+  return commonPrefix.slice(0, -1);
+};

valid-parenthesis.js

@@ -0,0 +1,50 @@
+var isValid = function (s) {
+  const validStrings = {
+    "(": ")",
+    "{": "}",
+    "[": "]",
+  };
+
+  var chars = s.split("");
+
+  if (chars.length % 2 !== 0) {
+    return false;
+  }
+
+  var isValid = true;
+  var listSize = chars.length;
+
+  for (let i = 0; i < listSize; i++) {
+    var char = chars[i];
+    var nextChar = chars[i + 1];
+    var dictValue = validStrings[char];
+
+    var charFromReverse = chars[s.length - (i + 1)];
+
+    if (nextChar == dictValue) {
+      i++;
+      continue;
+    }
+
+    if (dictValue == charFromReverse) {
+      listSize--;
+      continue;
+    }
+
+    if (!(nextChar == dictValue)) {
+      isValid = false;
+    }
+  }
+  return isValid;
+};
+
+// Ou o match é o próximo caracter  ou é o mesmo indice de trás pra frente do array.
+// senão tiver match,
+
+// "()"
+// "(){}()"
+// "({[()]})"
+// "([])"
+// "(([]){})"
+
+console.log(isValid("()"));