e.cpp

//
//  29-10-2013.cpp
//  wdi2013
//
//  Created by Stanisław Chmiela on 29.10.2013.
//  Copyright (c) 2013 Stanisław Chmiela. All rights reserved.
//

#include <cstdio>
using namespace std;

const int max = 51;

int main() {
    int e[max], factorial[max], current;
    bool end = 0;
    for(int i = 0; i<max; i++) {
        e[i] = factorial[i] = 0;
    }
    
    factorial[0] = 1;
    e[0] = 1;
    
    current = 1;
    
    while(!end) {
        int r = 0;
        for(int i = max; i>=0; i--) {
            e[i] = e[i] + r + factorial[i];
            r = e[i]/10;
            e[i] = e[i]%10;
        }
        current++;
        r = 0;
        for(int i = 0; i<max; i++) {
            r = 10*r + factorial[i];
            factorial[i] = r/current;
            r = r%current;
        }
        
        end = 1;
        
        for(int i = 0; i<max; i++) {
            if(factorial[i] != 0) {
                end = 0;
                break;
            }
        }
    }
    
    printf("%d.",e[0]);
    for(int i = 1; i<max; i++) {
        printf("%d",e[i]);
    }
    printf("\n");
    
    return 0;
}