Hello every one,
I have spent the past week working on this assignment and i'm hoping to get some help on what I need to do to correct my sift and get it to print out.
the assignment is to open an encrypted file, count the occurrence of each alphabetic character in the file. find the highest occurring letter and use that to find the shift, then apply the sift to the file in order to decipher and then print out the deciphered txt.
sorry for any miss spellings, and thanks for any help you may have
#include <fstream>
#include <iostream>
#include <string>
usingnamespace std;
int main(){
string word;
ifstream txt;
int arr[26] = { 0 };
char ch;
//opens the file encrypted.txt
txt.open("C:/encrypted.txt");
if (txt.is_open()){ // need to find # of eatch charikter not the # of individual char
/*while (txt.get(ch)){ // reads char one at a time
if (isalpha(ch)){ //checks if it is alphebetikal
ch = tolower(ch); //switches all the char to lower char
int index = ch - 'a'; //the 'a' will set your array 0-26
arr[index]++; //this will increas the count for eatch letter on the array
}
}*/
while (!txt.eof()){ //untill you reatch the end of the file ....
txt >> ch; //set the content of file txt into char ch
ch = tolower(ch) - 'a'; //the a will set your array 0-26
arr[ch]++; //this will increas the count for eatch letter on the array
}
}
else{ //if the file is not open
cout << "hav not found file, will now end program";
getchar();
getchar();
return 0;
}
int maxIndex = 0;
int position;
for (int i = 0; i < 26; i++)
{
if (i == 1)
{
maxIndex = arr[i];
position = 1;
}
elseif (arr[i] >= maxIndex){
maxIndex = arr[i];
position = i;
}
}
// this will calculate the shift and then shift the char in the txt to the right letters
int shift;
shift = position - 4;
txt.open("C:/encrypted.txt");
while (!txt.eof()){
while (txt.get(ch)){ // reads char one at a time
if (ch >= 'A' && ch <= 'Z')
{
ch = (char)(((ch - shift - 'A' + 26) % 26) + 'A');
}
elseif (ch >= 'a' && ch <= 'z')
{
ch = (char)(((ch - shift - 'a' + 26) % 26) + 'a');
}
}
}
cout << ch;
//pouse and exit
getchar();
getchar();
return 0;
}
Ok, so this is what I have now, a made some changes and tried a few things but my output is now a downward arrow. is there any way to get this to print out as a string.
I tried creating a string var and += ch to it both inside and outside the of the final shift loops but I got nothing back.
#include <fstream>
#include <iostream>
#include <string>
usingnamespace std;
int main(){
string word;
ifstream txt;
int arr[26] = { 0 };
char ch;
//opens the file encrypted.txt
txt.open("C:/encrypted.txt");
if (txt.is_open()){ // need to find # of eatch charikter not the # of individual char
while (!txt.eof()){ //untill you reatch the end of the file ....
txt >> ch; //set the content of file txt into char ch
if (isalpha(ch)){
ch = tolower(ch) - 'a'; //the a will set your array 0-26
arr[ch]++; //this will increas the count for eatch letter on the array
}
}
}
else{ //if the file is not open
cout << "hav not found file, will now end program";
getchar();
getchar();
return 0;
}
int maxIndex = 0;
int position =0;
for (int i = 0; i < 26; i++)
{
int position, maxIndex = 0;
for (int i = 0; i < 26; ++i)
{
if (arr[i] > maxIndex)
{
maxIndex = arr[i];
position = i;
}
}
}
int shift = position - 4; // becous the highest # in the array is equivelent to e in a decripted file,
//shift is = to difrence betwean the highest #s lowcation in the array and 'e' whitch address should = 4
// this will calculate the shift and then shift the char in the txt to the right letters
txt.open("C:/encrypted.txt");
string txtF;
while (txt >> ch)
{
if (isupper(ch))
{
ch = ((ch - shift - 'A' + 26) % 26) + 'A';
}
elseif (ch >= 'a' && ch <= 'z')
{
ch = ((ch - shift - 'a' + 26) % 26) + 'a';
}
}
cout << ch;
//pouse and exit
getchar();
getchar();
return 0;
}
Ps: thank you both for taking the time to help so far
If the code that reads the input file the first time works then use it again write the output:
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txt.open("C:/encrypted.txt");
if (txt.is_open()){
while (!txt.eof()){
txt >> ch;
if (isupper(ch)) {
ch = ((ch - shift - 'A' + 26) % 26) + 'A';
} elseif (islower(ch)) { // note that I used islower()
ch = ((ch - shift - 'a' + 26) % 26) + 'a';
}
cout << ch;
}
Actually this code isn't quite right. eof() won't be true until after you try to read past it, so this code will output one extra character. Try this instead:
1 2 3 4 5 6 7 8 9 10 11 12
txt.open("C:/encrypted.txt");
if (txt.is_open()){
txt >> ch; // get the first character
while (!txt.eof()){
if (isupper(ch)) {
ch = ((ch - shift - 'A' + 26) % 26) + 'A';
} elseif (islower(ch)) { // note that I used islower()
ch = ((ch - shift - 'a' + 26) % 26) + 'a';
}
cout << ch;
txt >> ch; // get the next character
}
If this works, then change the input code to do it the same way.
One more thing: when you're dong reading txt, close it with txt.close(). Do this both times after reading it.
