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;
}