Merge pull request #11 from rroque98/master

Add chapter 1 JavaScript solutions to 1.2 - 1.6

Author: fvntr

JavaScript/chapter01/1.2 - Check Perm/rroque98_sol.js

@@ -0,0 +1,37 @@
+/*Given two strings, write a method to decide
+if one is apermutation of the other permutation:*/
+
+const isPermutation = (str1, str2) =>{
+  if (str1.length !== str2.length) {
+    return false;
+  }
+  const obj1 = determineCharCount(str1);
+  const obj2 = determineCharCount(str2);
+  for (let char of str1) {
+    if (obj1[char] !== obj2[char]) {
+      return false;
+    }
+  }
+  return true;
+  //******** helper function ******
+  function determineCharCount(string) {
+    const obj = {};
+    for (let char of string) {
+      if (obj[char] !== undefined) {
+        obj[char]++;
+      } else {
+        obj[char] = 1;
+      }
+    }
+    return obj;
+  }
+}
+
+// Tests:
+  console.log(isPermutation('abc', 'abb') === false);
+  console.log(isPermutation('abb', 'abc') === false);
+  console.log(isPermutation('aaa', 'abc') === false);
+  console.log(isPermutation('abc', 'abcd') === false);
+  console.log(isPermutation('abc', 'bac') === true);
+  console.log(isPermutation('', '') === true);
+  console.log(isPermutation('12', '21') === true);

JavaScript/chapter01/1.3 - URLify/rroque98_sol.js

@@ -0,0 +1,8 @@
+// Write a method to replace all spaces within a string with '%20'
+
+const URLify = (string) => string.split(' ').join('%20');
+
+// Tests:
+console.log(URLify('Hello World') === 'Hello%20World');
+console.log(URLify('') === '');
+console.log(URLify('This is an example') === 'This%20is%20an%20example');

JavaScript/chapter01/1.4 - PalinPerm/rroque98_sol.js

@@ -0,0 +1,28 @@
+// Given a string, write a function to check if it is a permutation of a palindrome
+
+const isPalindromePermutation = (str) => {
+  const strNoSpaces = str.split(' ').join('');
+  const obj = {};
+  var oddCount = 0;
+  for (let char of strNoSpaces) {
+    if (obj[char] !== undefined) {
+      obj[char]++;
+    } else {
+      obj[char] = 1;
+    }
+  }
+  for (let key in obj) {
+    if (obj[key] % 2) {
+      oddCount++;
+    }
+    if (oddCount > 1) {
+      return false;
+    }
+  }
+  return true;
+}
+
+console.log(isPalindromePermutation('tact coa') === true);
+console.log(isPalindromePermutation('tact cooa') === true);
+console.log(isPalindromePermutation('tacr coa') === false);
+console.log(isPalindromePermutation('tactr coa') === false);

JavaScript/chapter01/1.5 - OneAway/rroque98_sol.js

@@ -0,0 +1,43 @@
+/* There are 3 types of edits that can be made on a string:
+insert character, remove character, replace a character
+Given 2 strings write a function that will check if it is
+1 or 0 edits away*/
+
+const isOneAway = (str1, str2) => {
+  if (str1.length === str2.length) {
+    let errorCount = 0;
+    for (let i = 0; i < str1.length; i++) {
+      if (str1[i] !== str2[i]) {
+        errorCount++;
+      }
+      if (errorCount > 1) {
+        return false;
+      }
+    }
+  } else {
+    let errorCount = 0;
+    const longestStr = findLongestStr(str1, str2);
+    let x = 0;
+    for(let i = 0; i < longestStr; i++) {
+      if (str1[i] !== str2[x]) {
+        errorCount++;
+        x++;
+      }
+      if (errorCount > 1) {
+        return false;
+      }
+      x++;
+    }
+    // ***** Helper functions ********
+    function findLongestStr(str1, str2) {
+      str1 > str2 ? str1 : str2;
+    }
+  }
+  return true;
+}
+
+// TESTS
+console.log(isOneAway('pale', 'ple') === true);
+console.log(isOneAway('pales', 'pale') === true);
+console.log(isOneAway('pale', 'bale') === true);
+console.log(isOneAway('pale', 'bake') === false);

JavaScript/chapter01/1.6 - String Compression/rroque98_sol.js

@@ -0,0 +1,33 @@
+/* Implement a method to perform basic string 
+compression using the counts of repeated characters
+Ex: 'aabcccccaaa' would become a2b1c5a3
+*/
+
+const stringCompression = (str) => {
+  if (!str.length) {
+    return '';
+  }
+  var compStr = '';
+  var count = 1;
+  var currentChar = str[0];
+  for (let i = 1; i < str.length; i++) {
+    let char = str[i];
+    if (char === currentChar) {
+      count++;
+      if (i === str.length - 1) {
+        compStr += `${currentChar}${count}`;
+      }
+    } else {
+      compStr += `${currentChar}${count}`;
+      currentChar = char;
+      count = 1;
+    }
+  }
+  return compStr;
+}
+
+// TESTS
+console.log(stringCompression('aabcccccaaa') === 'a2b1c5a3');
+console.log(stringCompression('cccccccc') === 'c8');
+console.log(stringCompression('') === '');
+console.log(stringCompression('AabccCccaaa') === 'A1a1b1c2C1c2a3');