Reversing a String

[Chetan Vaghela]

How to reverse the string into one array in that array string is store in c language ?

I want to reverse the string in that array in which already stored...using only one array in program

[Frinavale]

1. Retrieve the length of the string and create an array of that length for storing the reversed characters
2. Declare 2 loop counters: one for keeping track of the position in the string and the other for keeping track of the position in the array.
3. Set the loop counter for keeping track of the position in the array to 0
4. Set the loop counter for keeping track of the position in the string to the length of the string
5. Implement a loop that uses the counter that keeps track of the position of in the string which moves towards the 0th index position in the string by decrementing the counter
6. Retrieve the character at that position
7. Add the character to the array using at the index that is stored in the loop counter used for keeping track of the position in the array
8. Increment the loop counter for keeping track of the position of the array.
9. Loop to step 5 (which will decrement the position in the string until 0 is reached)

-Frinny

[Frinavale]

The above solution only uses 1 array and the String.
If what you mean by "uses only 1 array" refers to the String itself (which is just an array of characters), then my above solution will not work for you.

The solution that you need will require shifting the characters until the are all reversed.

You could use a loop for this purpose...or you could implement a recursive function (a function that calls itself until some condition is met).

-Frinny

[whodgson]

One way would be to use the reverse() function defined in the header <algorithm>

char s[] = "abcde fghij";
    cout<<"print string s \n";
    cout<<s;//prints abcde fghij
    reverse(s,s+11);
    cout<<"\nprint reversed string s \n";
    cout<<s;//prints jihgf edcba
 

[donbock]

1. Draw a series of perhaps 5 boxes such that they form a row. This is your array variable. Number the boxes starting from zero, these are the array indices.
2. Populate your boxes with small distinguishable items (differing denominations of coins, pieces of candy, etc). These are the contents of your array.
3. Draw one box off to the side. This is a temporary variable that you may need.
4. Save a record of the starting arrangement of your array contents so you can check your results.
5. Now, reverse the array contents with the following rule: an array content can only be moved to an empty box.
6. Do this for both an odd and even sized array.

Pay attention to how you accomplished this. That's your algorithm. It is a lot easier to write a program once you truly understand the algorithm.

Are you reversing an array or a string?
If it is a string, then draw one more box at the end of the array and write "\0" in it. Don't move anything in or out of that box because you still need your reversed string to be null-terminated.

Pay attention to how you known when you're finished. If you keep going past the middle element you'll end up de-reversing the array.

[whodgson]

Another way after finding the length of a string of characters may be to position one pointer at the first character and a second pointer at the last character (the one before the NULL character) then use the swap() function defined in the header <algorithm> to swap these two characters before incrementing ptr#1 and decrementing ptr#2. Continue until the pointers reach the string center without passing.

[weaknessforcats]

It's already reversed. Just display it in the other direction.

[gtoal]

(elegantly...) string a in words the reversing is problem interesting more much A