M-ary number STR to n-ary number

’0‘ - ’9‘ Express ：0 - 9
‘a’ - ‘z’ Express ：36 - 61
’A‘ - ’Z‘ Express ：10 - 35
Input m Hexadecimal number str, Output n Hexadecimal number another

#include<cstdio>
#include<iostream>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<cctype>
#include<vector>
#include<stack>
#include<queue>
#include<ctime>
#include<utility>
#include<map>
#define ll long long
#define ld long double
#define ull unsigned long long
using namespace std;
const int INF = 0x3f3f3f3f3f;
const double eps = 1e-6;
const int maxn = 10000010;
char str[maxn],another[maxn];
int ten[maxn];
int switchToTen(int m);
void switchToAnother(int k,int n);
int main()
{
    
    int m,n,k;
    cin>>m>>n>>str;
    k = switchToTen(m);
    switchToAnother(k,n);

    return 0;
}
int switchToTen(int m)
{
    
    int i,j,len,k,c;
    len = strlen(str);
    k = 1;
    memset(ten,0,sizeof(ten));
    for(int i = 0;i<len;i++){
    
        for(int j=0;j<k;j++){
    
            ten[j] *= m;
        }
        if(str[i]>='0'&&str[i]<='9'){
    
            ten[0] += str[i]-'0';
        }
        else if(str[i]>='A'&&str[i]<='Z'){
    
            ten[0] += str[i]-'A'+10;
        }
        else if(str[i]>='a'&&str[i]<='z'){
    
            ten[0] += str[i]-'a'+36;
        }
        for(int j=c=0;j<k;j++){
    
            ten[j] += c;
            if(ten[j]>=10){
    
                c = ten[j] / 10;
                ten[j] %= 10;
            }
            else    c = 0;
        }
        while(c){
    
            ten[k++] = c % 10;
            c /= 10;
        }
    }
    int temp;
    for(int i=0,j=k-1;i<j;i++,j--){
    
        temp = ten[i];
        ten[i] = ten[j];
        ten[j] = temp;
    }
    return k;
}
void switchToAnother(int k,int n)
{
    
    int sum,r,t,d;
    sum = 1;
    r = 0;
    memset(another,0,sizeof(another));
    while(sum){
    
        sum = 0;
        for(int i=0;i<k;i++){
    
            d = ten[i] / n;
            sum += d;
            if(i==k-1){
    
                t = ten[i] % n;
                if(t>=0&&t<=9){
    
                    another[r] = t+'0';
                }
                else if(t>=10&&t<=35){
    
                    another[r] = t-10+'A';
                }
                else   another[r] = t-36+'a';
                r++;
            }
            else{
    
                ten[i+1] += ten[i]%n * 10;
            }
            ten[i] = d;
        }
    }
    for(int i=r-1;i>=0;i--){
    
        printf("%c",another[i]);
    }
    printf("\n");
}