Update keyFinder.js

Finally, there are several changes in the function keyFinder(str) that make it works well

Author: winsonrich

Ciphers/keyFinder.js

@@ -3,24 +3,40 @@ 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 =["is","Is","am","Am","are","Are","have","Have","has","Has","may","May","be","Be"];
-let key = 0; // return zero means the key can not be found
+const wordbank =[" 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
 let inStr = str.toString(); //convert the input to String
 let outStr = ""; // store the output value
-let wordInOutStr = ""; // temporary store the word inside the outStr, it is used for comparison
- for (let i=0; i<(52); i++){ //try the number of key shifted, the sum of character from a-z and A-Z is 26*2=52
-outStr = caesarCipherEncodeAndDecodeEngine(inStr,i); // use the encrytpion engine to decrypt the input string, shiftNum=i
-for ( let i=0; i<wordbank.length; i++){
-// use a loop to find the next digit of wordbank element and compare with outStr's digit
-for ( let j=0; j < wordbank[i].length; j++){
-wordInOutStr += outStr[i+j];
-}
-// this part need to be optimize with the calculation of the number of occurance 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] == wordInOutStr){
- return key=i; // return the key number if founded
-}
+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 encrytpion 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 occurance 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
 }