eight.cpp

#include <stdio.h>
#include <iostream>
#include <stdlib.h>
#include <time.h>
#define MAX 50
#define BILL 1000*1000*1000

using namespace std;

void nullArr (int *a) {
    for (int i=0; i<MAX; i++) {
        a[i]=0;
    }
}

void i2long(int num, int *a) {
    nullArr(a);
    int i=0;
    while(num) {
        i+=1;
        a[i]= num % 10;
        num = num / 10;
    }
    a[0]=i;
}

int complong(int *a, int *b) {
    if (a[0] < b[0]) return -1;
    if (a[0] > b[0]) return 1;
    for(int i=a[0]; i>=1; i--) {
        if (a[i] < b[i]) return -1;
        if (a[i] > b[i]) return 1;
    }
    return 0;
}

void mul(int *a, int b) {
    int c=0;
    for(int i=1; i<=a[0]; i++) {
        a[i] = a[i]*b+c;
        c = a[i] / 10;
        a[i] = a[i] % 10;
    }
    while(c > 0) {
        a[0] = a[0]+1;
        a[a[0]] = c % 10;
        c = c / 10;
    }
}

int mullong(int *a, int *b, int *c) {
    nullArr(c);
    int cr,k;
    if (b[0]==1 && b[1]==0) {
        c[0]=1;
        return 0;
    }
    for(int i=1; i<=a[0]; i++) {
        for(int j=1; j<=b[0]; j++) {
            cr = a[i]*b[j];
            k = i+j-1;
            while(cr>0) {
                cr = cr+c[k];
                c[k] = cr % 10;
                cr = cr / 10;
                k > c[0]&&(c[0]=k);
                k +=1;
            }
        }
    }
    return 0;
}
void pow2(int P, int *a) {
    nullArr(a);
    a[0]=1;
    a[1]=1;
    if (P)
        for (unsigned int i=0; i<P; i++) {
            mul(a,2);
        }
}

void writelong(int *a) {
    for(int i=a[0]; i>=1; i--) {
        cout << a[i];
    }
}

void sublong(int *a, int *b) {
    int c=0;
    for(int i=1; i<=a[0]; i++) {
        c = c+a[i]-b[i]+10;
        a[i] = c % 10;
        c = c < 10?-1:0;
    }
}


int asd(long a) {
    if (a % 8==0 || a==0)
        return 3;
    if (a % 4==0)
        return 2;
    if (a % 2==0)
        return 1;
    return 0;
}

void mas_rec(int n, long *arr, int *mar) {
    int i;
    for (i=0; i<n; i++) {
        arr[i]=asd(arr[i]);
    };
    for (i=0; i<4; i++)
        mar[i]=0;
    for (i=0; i<n; i++)
        mar[arr[i]]+=1;
}

int main(void) {
    int a[MAX],b[MAX], c[MAX], t;
    nullArr(a);
    nullArr(b);
    nullArr(c);
    long arr[100];
    int mar[4],m,m1;
    long res;
    unsigned long i,n=0;
    cin >> n;
    for (i=0; i<n; i++)
        cin >> arr[i];
    mas_rec(n, arr, mar);
    m = (1 + (mar[1]+1)*mar[1]/2 + mar[2]);
    i2long(m,c);
    pow2(n-mar[0],b);
    sublong(b, c);
    pow2(mar[0],a);
    mullong(a,b,c);
    i2long(BILL,a);
    if (complong(c,a)==1)
        cout << "too many eights";
    else
        writelong(c);
    return 0;
}