codeofrce:http://codeforces.com/contest/697/problem/B
qduoj:https://qduoj.com/problem/120/
将科学计数法表示的数字转化为一般数字
Java的高精度类：
import java.util.Scanner;public class Main {static Scanner sc = new Scanner(System.in);public static void main(String[] args) {System.out.println(sc.nextBigDecimal().stripTrailingZeros().toPlainString());}}c++的模拟：
#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cstdio>
#include<vector>
#include<queue>
#include<set>
#include<map>
using namespace std;
int main()
{string p, num, q, first, last;while(cin >> p){int len = p.length();int e = p.find_first_of('e'), n = 0;int point = p.find_first_of('.');num = p.substr(0, e);q = p.substr(e+1, len - e);for(int i = 0; i < q.length(); i++)n = n*10 + q[i] - '0';first = p.substr(0, point);last = p.substr(point+1, e-point-1);if(first.length() == 1 && first[0] == '0' && last.find_first_not_of('0') >= last.length()){cout << 0 << endl;continue;}if(last.find_first_not_of('0') >= last.length()){cout << first;for(int i = 0; i < n; i++)cout<<0;cout << endl;continue;}if(first.length() == 1 && first[0] == '0' ){if(n == 0){cout << 0 << "." << last << endl;continue;}if(last.length() > n){string ans = last.substr(0, n);int flag = 0;if(ans.find_first_not_of('0') >= ans.length())cout << 0;else{for(int k = 0; k < ans.length(); k++){if(ans[k] == '0' && flag == 0)continue;else{flag = 1;cout << ans[k];}}}cout <<"."<<last.substr(n, last.length()) << endl;}else{cout << last;for(int i = 0; i < n-last.length(); i++)cout << 0;cout << endl;}continue;}else{if(n == 0){cout << first << "." << last << endl;continue;}if(last.length() > n){cout << first << last.substr(0, n) <<"."<<last.substr(n, last.length()) << endl;}else{cout << first << last;for(int i = 0; i < n-last.length(); i++)cout << 0;cout << endl;}continue;}}return 0;
}