new commit

src/brackets/index.js

@@ -4,6 +4,39 @@
  * @param {string} str The string of brackets.
  * @returns {"valid" | "invalid"} Whether or not the string is valid.
  */
-function isValid(str) {}
 
-module.exports = isValid;
+function isValid(str) {
+    let stack = [];
+    // For each char in the bracket
+  for(let i = 0; i < str.length; i++) {
+        let x = str[i];
+
+        if( x == '[' || x == '(' || x == '{' ) {
+        stack.push(x);
+        continue;
+        }
+
+        if (stack.length === 0 ) {
+          return "invalid"
+        }
+
+        const top = stack.pop();
+        if( x == ')' && top != '(' ) { 
+          return "invalid"; 
+        }
+         if( x  == ']' && top != '[' ) {
+           return "invalid"; 
+          }
+          if( x == '}' && top != '{' ) {
+             return "invalid"; 
+            }
+
+        }
+
+    return stack.length === 0 ? "valid" : "invalid";
+
+     };
+
+   console.log(isValid("]]"));
+
+   module.exports = isValid;

src/roman-numerals/index.js

@@ -4,6 +4,34 @@
  * @param {string} roman The all-caps Roman numeral between 1 and 3999 (inclusive).
  * @returns {number} The decimal equivalent.
  */
-function romanToDecimal(roman) {}
 
-module.exports = romanToDecimal;
+
+function romanToDecimal(roman) {
+    let romanToDecimal = {
+        I : 1,
+        V : 5,
+        X : 10,
+        L : 50,
+        C : 100,
+        D : 500,
+        M : 1000,
+    }
+    let result = 0;
+
+    for( let i = 0; i < roman.length; i++){
+        let currSym = romanToDecimal[roman[i]];
+        let nextSym = romanToDecimal[roman[i + 1]];
+
+        if(nextSym && nextSym > currSym) {
+            result += nextSym - currSym
+            i++
+        } else {
+            result += currSym
+        }
+
+    };
+    return result
+};
+
+
+module.exports = romanToDecimal;

src/transpose/index.js

@@ -4,6 +4,9 @@
  * @param {number[]} array The array to transpose
  * @returns {number[]} The transposed array
  */
-function transpose(array) {}
 
-module.exports = transpose;
+function transpose(array) {
+    return array[0].map((item, index) => array.map((cur) => cur[index]));
+};
+
+module.exports = transpose;