题解

#include<iostream>
using namespace std;
int a[2001]={6};
int c[10]={6,2,5,5,4,5,6,3,7,6};
int num,num1,num2;
int main(){
    cin>>num;
    for(int i=1;i<=2000;i++){
		num2=i;
		while(num2>=1){
			a[i]=a[i]+c[num2%10];
			num2/=10;
		}
	}
	num1=0;
    for(int i=0;i<=750;i++)
    	for(int j=0;j<=750;j++)
    		if(num==a[i]+a[j]+a[i+j]+4) num1++;
    cout<<num1;
    return 0;
}

by QFIT