giúp em với ạaaaaaaaaaaaaaaa.

$\color{#1fdb91}{\texttt{C}}\color{#0aaec9}{\texttt{+}}\color{#e9418e}{\texttt{+}}$

#include <bits/stdc++.h>

#define ll long long

using namespace std;

int main() {
    
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    
    string n, k, res; cin >> n >> k;
    ll tmp;
    for (ll i=n.size()-1; i>=0; --i) {
        tmp = n[i]-'0' + k[i]-'0';
        res = char(tmp % 10 + '0') + res;
    }
    
    while (res[0] == '0' && res.size() > 1) res.erase(0, 1);
    
    cout << res;
    
}

// Author : Daoanhviet96
// Language : C++

$\\$
\begin{array}{c|c|c}\color{#ffd710}{\texttt{\{}} \color{#8655d6}{\texttt{\{}}\ \ \color{#8cdcda}{\text{Daoanhviet96}}\ \ \color{#8655d6}{\texttt{\}}} \color{#ffd710}{\texttt{\}}}\end{array}

#include<iostream>
using namespace std;
#include<string.h>
#pragma warning(disable:4996)
void tkt(char s[], int vt, char kitu)
{
 int n = strlen(s);                           
 for (int i = n - 1; i >= vt; i--)
 {
  s[i + 1] = s[i];
 }
 s[vt] = kitu;
 s[n + 1] = '\0';
}
int main()
{
 char s1[10],s2[10];
 cin >> s1 >> s2;
 if (strlen(s1) > strlen(s2))
 {
  int sl_them = strlen(s1) - strlen(s2);

  for (int i = 1; i <= sl_them; i++)
  {
   tkt(s2, 0, '0');
  }
 }
 else if (strlen(s1) < strlen(s2))
 {
  int sl_them = strlen(s2) - strlen(s1);
  for (int i = 1; i <= sl_them; i++)
  {
   tkt(s1, 0, '0');
  }
 }

 int nho = 0; 
 int kq = 0; 
 char ket_qua[11] = "";
 int k = 0; 

 for (int i = strlen(s2) - 1; i >= 0; i--)
 {
  kq = (s1[i] - 48) + (s2[i] - 48) + nho;
  nho = kq / 10; 
  ket_qua[k] = (kq % 10) + 48;
  k++;
 }

if (nho != 0)

{

  ket_qua[k] = nho + 48;

} 

for (int i = strlen(ket_qua) - 1 ; i >= 0; i--)

{

  if (i==strlen(ket_qua)-1)
  {
   if (ket_qua[i] == 0)
   {}
  }
  else
  {
   cout << ket_qua[i];
  }
}

}

 return 0;
}