Renaming files according to naming convention (#158)

Ciphers/KeyFinder.js

@@ -0,0 +1,148 @@
+/******************************************************
+ Find and retrieve the encryption key automatically
+ Note: This is a draft version, please help to modify, Thanks!
+ ******************************************************/
+function keyFinder (str) { // str is used to get the input of encrypted string
+  const wordBank = [
+    'I ',
+    'You ',
+    'We ',
+    'They ',
+    'He ',
+    'She ',
+    'It ',
+    ' the ',
+    'The ',
+    ' of ',
+    ' is ',
+    'Is ',
+    ' am ',
+    'Am ',
+    ' are ',
+    'Are ',
+    ' have ',
+    'Have ',
+    ' has ',
+    'Has ',
+    ' may ',
+    'May ',
+    ' be ',
+    'Be ']
+  // let wordbankelementCounter = 0;
+  // let key = 0; // return zero means the key can not be found
+  const inStr = str.toString() // convert the input to String
+  let outStr = '' // store the output value
+  let outStrElement = '' // temporary store the word inside the outStr, it is used for comparison
+  for (let k = 0; k < 26; k++) { // try the number of key shifted, the sum of character from a-z or A-Z is 26
+    outStr = caesarCipherEncodeAndDecodeEngine(inStr, k) // use the encryption engine to decrypt the input string
+
+    // loop through the whole input string
+    for (let s = 0; s < outStr.length; s++) {
+      for (let i = 0; i < wordBank.length; i++) {
+        // initialize the outStrElement which is a temp output string for comparison,
+        // use a loop to find the next digit of wordBank element and compare with outStr's digit
+        for (let w = 0; w < wordBank[i].length; w++) {
+          outStrElement += outStr[s + w]
+        }
+
+        // console.log( k + outStrElement + wordBank[i] );//debug
+
+        // this part need to be optimize with the calculation of the number of occurrence of word's probabilities
+        // linked list will be used in the next stage of development to calculate the number of occurace of the key
+        if (wordBank[i] === outStrElement) {
+          return k // return the key number if founded
+        }
+
+        outStrElement = '' // reset the temp word
+      } // end for ( let i=0; i < wordBank.length; i++)
+    }
+  }
+  return 0 // return 0 if found nothing
+}
+
+/* this sub-function is used to assist the keyFinder to find the key */
+function caesarCipherEncodeAndDecodeEngine (inStr, numShifted) {
+  const shiftNum = numShifted
+  let charCode = 0
+  let outStr = ''
+  let shiftedCharCode = 0
+  let result = 0
+
+  for (let i = 0; i < inStr.length; i++) {
+    charCode = inStr[i].charCodeAt()
+    shiftedCharCode = charCode + shiftNum
+    result = charCode
+
+    if ((charCode >= 48 && charCode <= 57)) {
+      if (shiftedCharCode < 48) {
+        let diff = Math.abs(48 - 1 - shiftedCharCode) % 10
+
+        while (diff >= 10) {
+          diff = diff % 10
+        }
+        document.getElementById('diffID').innerHTML = diff
+
+        shiftedCharCode = 57 - diff
+
+        result = shiftedCharCode
+      } else if (shiftedCharCode >= 48 && shiftedCharCode <= 57) {
+        result = shiftedCharCode
+      } else if (shiftedCharCode > 57) {
+        let diff = Math.abs(57 + 1 - shiftedCharCode) % 10
+
+        while (diff >= 10) {
+          diff = diff % 10
+        }
+        document.getElementById('diffID').innerHTML = diff
+
+        shiftedCharCode = 48 + diff
+
+        result = shiftedCharCode
+      }
+    } else if ((charCode >= 65 && charCode <= 90)) {
+      if (shiftedCharCode <= 64) {
+        let diff = Math.abs(65 - 1 - shiftedCharCode) % 26
+
+        while ((diff % 26) >= 26) {
+          diff = diff % 26
+        }
+        shiftedCharCode = 90 - diff
+        result = shiftedCharCode
+      } else if (shiftedCharCode >= 65 && shiftedCharCode <= 90) {
+        result = shiftedCharCode
+      } else if (shiftedCharCode > 90) {
+        let diff = Math.abs(shiftedCharCode - 1 - 90) % 26
+
+        while ((diff % 26) >= 26) {
+          diff = diff % 26
+        }
+        shiftedCharCode = 65 + diff
+        result = shiftedCharCode
+      }
+    } else if ((charCode >= 97 && charCode <= 122)) {
+      if (shiftedCharCode <= 96) {
+        let diff = Math.abs(97 - 1 - shiftedCharCode) % 26
+
+        while ((diff % 26) >= 26) {
+          diff = diff % 26
+        }
+        shiftedCharCode = 122 - diff
+        result = shiftedCharCode
+      } else if (shiftedCharCode >= 97 && shiftedCharCode <= 122) {
+        result = shiftedCharCode
+      } else if (shiftedCharCode > 122) {
+        let diff = Math.abs(shiftedCharCode - 1 - 122) % 26
+
+        while ((diff % 26) >= 26) {
+          diff = diff % 26
+        }
+        shiftedCharCode = 97 + diff
+        result = shiftedCharCode
+      }
+    }
+    outStr = outStr + String.fromCharCode(parseInt(result))
+  }
+  return outStr
+}
+
+console.log('Testing: ' + keyFinder('test')) // returns 0