c++ - 我必须更改我的数字的最后一位和第一位，但不能仅对整数或循环使用函数。例如从12345到52341

Question

#include <iostream>
using namespace std;
int main()
{
// Here I seperate my number because at first I have to seperate and then I have to change the first digit and last digit.
    int numri, shifrat, i = 0, a, shuma = 0, m, d;
    cout << "Jep nje numer \n";
    cin >> numri;
    m = numri;
    while (numri != 0) {
        i++;
        numri = numri / 10;     
    }
    d = pow(10, i - 1);
    numri = m; 
    while (numri != 0) {
        shifrat = numri / d;
        cout << shifrat << "  ";
        numri = numri % d;
        d = d / 10;
    }

//Now after that I have to change the last digit and first digit. Please help me.
//But I'm not allowed to use functions or swap only integers and loops or conditions.

    cin.get();
}

有人能帮助我吗？

Answer 1

交换数字ABCDEF中的第一位和最后一位--FBCDEA

num = 12345
res = 52341

这个想法是:

52341 = 12345-10005 + 50001

第一位数fd = num％10

小数点后乘数df = 1

until num is not zero we do
last digit ld = num
num = num / 10
if num != 0 decimal places multiplier df = df*10

结果= ABCDEF-F-A * 100000 + A + F * 100000

int m = numri;
int ld = 0; // last digit(most)
int fd = numri % 10; // first digit(least)
int df = 1; // last digit multiplier 10^n where n is decimal places
while (numri != 0) {
    ld = numri;// this will be the last digit in last iteration
    numri = numri / 10;
    if(numri) df = df * 10;
}
int res = m - fd - ld * df + fd * df + ld;
cout<<res;

例:

if the num = 12345

fd = 12345 % 10 =5
df = 1

num = 12345 / 10 = 1234
df = df*10 = 10

num = 1234 / 10 = 123
df = df*10 = 100

num = 123 / 10 = 12
df = df*10 = 1000

fd = num = 12
num = 12 / 10 = 1
df = df*10 = 10000

fd = num = 1
num = 1/10 =0
df not changed
loop exit

result = 12345 - 5  - 1*10000 + 1 + 5*10000 = 62341