CodeForces 620B Grandfather Dovlet’s calculator

#include<cstdio>
#include<cstring>
#include<cmath>
#include<stack>
#include<vector>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;

int x[20];

int main()
{
int a,b;
int ans=0;
x[0]=6;
x[1]=2;
x[2]=5;
x[3]=5;
x[4]=4;
x[5]=5;
x[6]=6;
x[7]=3;
x[8]=7;
x[9]=6;

scanf("%d%d",&a,&b);
for(int i=a;i<=b;i++)
{
int num=i;
while(num)
{
ans=ans+x[num%10];
num=num/10;
}
}
printf("%d\n",ans);
return 0;
}