Codeforces Round #362 (Div. 2) B 模擬

連結：戳這裡

Barney is standing in a bar and starring at a pretty girl. He wants to shoot her with his heart arrow but he needs to know the distance between him and the girl to make his shot accurate.
Barney asked the bar tender Carl about this distance value, but Carl was so busy talking to the customers so he wrote the distance value (it's a real number) on a napkin. The problem is that he wrote it in scientific notation. The scientific notation of some real number x is the notation of form AeB, where A is a real number and B is an integer and x = A × 10B is true. In our case A is between 0 and 9 and B is non-negative.

Barney doesn't know anything about scientific notation (as well as anything scientific at all). So he asked you to tell him the distance value in usual decimal representation with minimal number of digits after the decimal point (and no decimal point if it is an integer). See the output format for better understanding.

Input
The first and only line of input contains a single string of form a.deb where a, d and b are integers and e is usual character 'e' (0 ≤ a ≤ 9, 0 ≤ d < 10100, 0 ≤ b ≤ 100) — the scientific notation of the desired distance value.

a and b contain no leading zeros and d contains no trailing zeros (but may be equal to 0). Also, b can not be non-zero if a is zero.

Output
Print the only real number x (the desired distance value) in the only line in its decimal notation.

Thus if x is an integer, print it's integer value without decimal part and decimal point and without leading zeroes.

Otherwise print x in a form of p.q such that p is an integer that have no leading zeroes (but may be equal to zero), and q is an integer that have no trailing zeroes (and may not be equal to zero).

Examples
input
8.549e2
output
854.9
input
8.549e3
output
8549
input
0.33e0
output
0.33

題意：

給出一個科學計數法表示的數，輸出十進位制下的數

思路：

有一個坑點就是 a.0e0 答案是a

程式碼：

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<string>
#include<vector>
#include <ctime>
#include<queue>
#include<set>
#include<map>
#include<stack>
#include<iomanip>
#include<cmath>
#define mst(ss,b) memset((ss),(b),sizeof(ss))
#define maxn 0x3f3f3f3f
#define MAX 1000100
///#pragma comment(linker, "/STACK:102400000,102400000")
typedef long long ll;
typedef unsigned long long ull;
#define INF (1ll<<60)-1
using namespace std;
string s;
char p[10010];
int main(){
    cin>>s;
    int a=s[0]-'0';
    int t=2,cnt=0;
    while(s[t]!='e') {
        p[cnt++]=s[t];
        t++;
    }
    t=s.size()-1;
    int b=0,x=1;
    while(s[t]!='e'){
        b=b+(s[t]-'0')*x;
        t--;
        x*=10;
    }
    cout<<a;
    if(b==0){
        if(cnt==1 && p[0]=='0') return 0;
        cout<<".";
        for(int i=0;i<cnt;i++) cout<<p[i];
        cout<<endl;
        return 0;
    }
    t=0;
    int i;
    for(i=0;i<b && t<cnt;i++){
        cout<<p[i];
        t++;
    }
    if(i==b && t==cnt) return 0;
    if(t<cnt){
        cout<<".";
        for(i=t;i<cnt;i++) cout<<p[i];
        return 0;
    }
    if(i<b){
        while(i<b){
            cout<<0;
            i++;
        }
        return 0;
    }
    return 0;
}