Algorithm Task

src/brackets/index.js

@@ -4,6 +4,22 @@
  * @param {string} str The string of brackets.
  * @returns {"valid" | "invalid"} Whether or not the string is valid.
  */
-function isValid(str) {}
+function isValid(str) {
+
+ let stck = []
+
+ for(let i = 0; i < str.length; i++){
+        let char = stck[stck.length - 1]
+        if(str[i] == "(" || str[i] == "{" || str[i] == "[") {
+            stck.push(str[i]);
+
+        } else if ((char == "(" && str[i] == ")") || (char == "{" && str[i] == "}" || (char == "[" && str[i] == "]"))){
+            stck.pop();
+        }else{
+            return "invalid";
+        }
+ }
+return stck.length ? "invalid" : "valid";
+}
 
 module.exports = isValid;

src/roman-numerals/index.js

@@ -4,6 +4,38 @@
  * @param {string} roman The all-caps Roman numeral between 1 and 3999 (inclusive).
  * @returns {number} The decimal equivalent.
  */
-function romanToDecimal(roman) {}
+function romanToDecimal(roman) {
+
+    const romansValue = {"M":1000, "D":500, "C":100, "L":50, "X":10, "V":5, "I":1};
+
+    const array = roman.split('');
+
+    var total = 0;
+
+    var currentValue;
+
+    var nextValue;
+
+    var n = array.length;
+
+    for(let i = 0; i < n; i++){
+
+        currentValue = romansValue[array[i]];
+
+        nextValue = romansValue[array[i + 1]];
+
+        if(currentValue >= nextValue){
+            total += (currentValue);
+
+        } else if(currentValue < nextValue){
+            total -= (currentValue);
+
+        } else if(currentValue && !nextValue){
+            total += currentValue;
+        }
+
+    }
+    return total;
+}
 
 module.exports = romanToDecimal;

src/transpose/index.js

@@ -4,6 +4,20 @@
  * @param {number[]} array The array to transpose
  * @returns {number[]} The transposed array
  */
-function transpose(array) {}
+function transpose(array) {
+
+        for (var i = 0; i < array.length; i++) {
+
+          for (var j = 0; j < i; j++) {
+
+            const temp = array[i][j];
+
+            array[i][j] = array[j][i];
+
+            array[j][i] = temp;
+          }
+        }
+
+}
 
 module.exports = transpose;