Solved bracket task

src/brackets/index.js

@@ -4,6 +4,32 @@
  * @param {string} str The string of brackets.
  * @returns {"valid" | "invalid"} Whether or not the string is valid.
  */
-function isValid(str) {}
+function isValid(str) {
+    const openBrackets = [];
+
+    if(str.charAt(0) == '}' || str.charAt(0) == ')' || str.charAt(0) == ']'){
+        return 'invalid';
+    }else {
+        for(let bracket of str){
+            if(bracket == '{' || bracket == '(' || bracket == '['){
+                openBrackets.push(bracket);
+            }
+
+            let lastElement = openBrackets.slice(-1);
+
+            if(bracket == '}' && lastElement == '{'){
+                openBrackets.pop();
+            }else if(bracket == ')' && lastElement == '('){
+                openBrackets.pop();
+            }else if(bracket == ']' && lastElement == '['){
+                openBrackets.pop();
+            }
+            // else {
+            //     return 'invalid'
+            // }
+        }
+    }
+    return openBrackets.length > 0 ? 'invalid' : 'valid';
+}
 
 module.exports = isValid;

src/brackets/index.ts

@@ -0,0 +1,36 @@
+/**
+ * Implement the solution to brackets
+ *
+ * @param {string} str The string of brackets.
+ * @returns {"valid" | "invalid"} Whether or not the string is valid.
+ */
+function isValid(str : string) {
+
+    const openBrackets : string[] = [];
+
+    if(str.charAt(0) == '}' || str.charAt(0) == ')' || str.charAt(0) == ']'){
+        return 'invalid';
+    }else {
+        for(let bracket of str){
+            if(bracket == '{' || bracket == '(' || bracket == '['){
+                openBrackets.push(bracket);
+            }
+
+            let lastElement = openBrackets[openBrackets.length - 1];
+
+            if(bracket == '}' && lastElement == '{'){
+                openBrackets.pop();
+            }else if(bracket == ')' && lastElement == '('){
+                openBrackets.pop();
+            }else if(bracket == ']' && lastElement == '['){
+                openBrackets.pop();
+            }
+            // else {
+            //     return 'invalid'
+            // }
+        }
+    }
+    return openBrackets.length > 0 ? 'invalid' : 'valid';
+}
+
+module.exports = isValid;

src/roman-numerals/index.js

@@ -4,6 +4,28 @@
  * @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 romanNumerial = {'I' : 1, 'V' : 5, 'X' : 10, 'L' : 50, 'C' : 100, 'D' : 500, 'M' : 1000}
+
+    let lastStrIndex = roman.length - 1
+    let decimal = romanNumerial[roman[lastStrIndex]];
+
+    // Looping from back
+    for(let i = lastStrIndex; i >= 0; i--){
+
+        let current = romanNumerial[roman[i]];
+        let next = romanNumerial[roman[i - 1]];
+
+        if( next >= current){
+            decimal += next;
+        }else if(next < current){
+            decimal -= next;
+        }
+    }
+
+    return decimal;
+
+}
 
 module.exports = romanToDecimal;

src/roman-numerals/index.ts

@@ -0,0 +1,31 @@
+/**
+ * Implement the solution in this function
+ *
+ * @param {string} roman The all-caps Roman numeral between 1 and 3999 (inclusive).
+ * @returns {number} The decimal equivalent.
+ */
+function romanToDecimal(roman:string) {
+
+    const romanNumerial: any = {'I' : 1, 'V' : 5, 'X' : 10, 'L' : 50, 'C' : 100, 'D' : 500, 'M' : 1000}
+
+    let lastStrIndex: number = roman.length - 1
+    let decimal: any = romanNumerial[roman[lastStrIndex]];
+
+    // Looping from back
+    for(let i = lastStrIndex; i >= 0; i--){
+
+        let current: any = romanNumerial[roman[i]];
+        let next:any = romanNumerial[roman[i - 1]];
+
+        if( next >= current){
+            decimal += next;
+        }else if(next < current){
+            decimal -= next;
+        }
+    }
+
+    return decimal;
+
+}
+
+module.exports = romanToDecimal;

src/transpose/index.js

@@ -4,6 +4,21 @@
  * @param {number[]} array The array to transpose
  * @returns {number[]} The transposed array
  */
-function transpose(array) {}
+function transpose(array) {
+    const newArr = [];
+
+    for(let i = 0; i < array[0].length; i++){
+        newArr.push([]);
+    }
+
+    for(let i = 0; i < array[0].length; i++){
+        for(let j=0; j < array.length; j++){
+
+            newArr[i].push(array[j][i])
+
+        }
+    }
+    return newArr;
+}
 
 module.exports = transpose;

src/transpose/index.ts

@@ -0,0 +1,25 @@
+/**
+ * Implement the solution in this function
+ *
+ * @param {number[]} array The array to transpose
+ * @returns {number[]} The transposed array
+ */
+function transpose(array: number[][]) {
+
+    const newArr: number[][] = [];
+
+    for(let i = 0; i < array[0].length; i++){
+        newArr.push([]);
+    }
+
+    for(let i = 0; i < array[0].length; i++){
+        for(let j=0; j < array.length; j++){
+
+            newArr[i].push(array[j][i])
+
+        }
+    }
+    return newArr;
+}
+
+module.exports = transpose;