进制转换

m进制转十进制

#include<cstdio>
#include<iostream>
#include<cstdlib>
#include<cstring>
char a[10000];
using namespace std;
int main()
{
   int n,m;
   int f=0;
   scanf ("%s%d",a,&m);
   for (int i=0;i<strlen(a);i++)
   {
        f*=m;
        if (a[i]=='A'||a[i]=='B'||a[i]=='C'||a[i]=='D'||a[i]=='E'||a[i]=='F')
        {
            f=f+(a[i]-'A'+10);
        }
        else
        {
            f=f+(a[i]-'0');
        }
   }
   printf ("%d",f);
   return 0;
}

十进制转k进制

#include<cstdio>
#include<iostream>
#include<ctime>
char a[1000];
using namespace std;
int main()
{
    int y=0,k,n,x;
    char z='A';
    scanf ("%d %d",&n,&x);
    while (n!=0)
    {   
          y++;
             a[y]=n%x;
          n=n/x;
          if (a[y]>9) a[y]=z+(a[y]-10); 
          else a[y]=a[y]+'0';
    }
    for (int i=y;i>0;i--)
    printf ("%c",a[i]);
    return 0;
}