Reverse integer number with while loop

Answer 1

I think it's like reversing a number like 123 ➡ 321.
Here's a general algorithm for it:
(1) Initialize a variable to keep track of the reversed number (rev) to 0
(2) Loop while num > 0
(a) Multiply rev by 10
(b) add remainder of num to rev
**a shorter way to think about all the above steps: rev = rev*10 + num%10;
(d) Divide num by 10
The result at the end of the loop is the number reversed. Example: 369
rev = 0
369 > 0, loop
rev = 0*10 + 369%10 = 9
num = 369/10 = 36
36 > 0, loop
rev = 9*10 + 36%10 = 96
num = 36/10 = 3
3 > 0, loop
rev = 96*10 + 3%10 = 963
num = 3/10 = 0
0 > 0 is false, stop loop
rev = 963, the reverse of 369

Answer 2

no just reverse every single character of number like
input : 768
output : 867

Answer 3

There's a much shorter way if using strings instead of numbers. C++ has a reverse method in the header <algorithm>.
Given a string of numbers (num), just pass it to reverse like so:
reverse(num.begin(), num.end());

Answer 4

Its very simple 1. Convert integre to character array
2. Use inverse character array like this code
#include <stdio.h> // printf
#include <stdlib.h> // malloc, free
#include <string.h> // strlen
int main()
{ char* s = "hello";
size_t l = strlen(s);
char* r = (char*)malloc((l + 1) * sizeof(char));
r[l] = '\0'; int i; for(i = 0; i < l; i++) { r[i] = s[l - 1 - i]; } printf("normal: %s\n", s); printf("reverse: %s\n", r); free(r); }
Finally return it to integer like this code
char myarray[5] = {'-', '1', '2', '3', '\0'};
int i;
sscanf(myarray, "%d", &i);

Answer 5

Jay Matthews I was more addressing the answer given by Ariela

Answer 6

https://code.sololearn.com/chhVtwlgKVLD/?ref=app

Answer 7

What do you mean? Like reverse an array of ints?

Answer 8

One sec I’ll write the code for you

Answer 9

int num = 768;
std::string s = std::to_string(num);
std::string reverse = “”;
char cstr[] = s.c_str();
int i = 0;
while (s.length() != reverse.length()){
i++;
reverse += cstr[cstr.length()-i];
}

Answer 10

This would be much easier done with a for loop or just using methods

Answer 11

And at the end just convert reverse to an int

Answer 12

decreasing integer loop