Efim just received his grade for the last test. He studies in a special school and his grade can be equal to any positive decimal fraction. First he got disappointed, as he expected a way more pleasant result. Then, he developed a tricky plan. Each second, he can ask his teacher to round the grade at any place after the decimal point (also, he can ask to round to the nearest integer).
There are t seconds left till the end of the break, so Efim has to act fast. Help him find what is the maximum grade he can get in no more than t seconds. Note, that he can choose to not use all t seconds. Moreover, he can even choose to not round the grade at all.
In this problem, classic rounding rules are used: while rounding number to the n-th digit one has to take a look at the digit n + 1. If it is less than 5 than the n-th digit remain unchanged while all subsequent digits are replaced with 0. Otherwise, if the n + 1 digit is greater or equal to 5, the digit at the position n is increased by 1 (this might also change some other digits, if this one was equal to 9) and all subsequent digits are replaced with 0. At the end, all trailing zeroes are thrown away.
For example, if the number 1.14 is rounded to the first decimal place, the result is 1.1, while if we round 1.5 to the nearest integer, the result is 2. Rounding number 1.299996121 in the fifth decimal place will result in number 1.3.
Input
The first line of the input contains two integers n and t (1 ≤ n ≤ 200 000, 1 ≤ t ≤ 109) — the length of Efim's grade and the number of seconds till the end of the break respectively.
The second line contains the grade itself. It's guaranteed that the grade is a positive number, containing at least one digit after the decimal points, and it's representation doesn't finish with 0.
Output
Print the maximum grade that Efim can get in t seconds. Do not print trailing zeroes.
Examples
Input
6 1 10.245
Output
10.25
Input
6 2 10.245
Output
10.3
Input
3 100 9.2
Output
9.2
Note
In the first two samples Efim initially has grade 10.245.
During the first second Efim can obtain grade 10.25, and then 10.3 during the next second. Note, that the answer 10.30 will be considered incorrect.
In the third sample the optimal strategy is to not perform any rounding at all.
题意:给出n和m表示有一长为n的字符串表示小明的分数(有小数点)m表示有m次操作机会,每次操作可以选择小数点后的任意一位进行四舍五入,求小明可以获得的最大分数。
思路:找到第一个大于等于5的数,然后依次进行四舍五入即可,(注意考虑进位,特判当小数点后一位进位的情况)
#include
#include
#include
using namespace std;
const int Max=2e5+10;
char str[Max],ch[Max],ha[Max];
int main()
{
int n,t,x,index=-1,f,a=0,b=0,tt=0,cnt=0;
scanf("%d%d%s",&n,&t,ha);
for(int i=0;i=5){//找到小数点后第一个大于5的数
index=i;
break;
}
}
f=len;
for(int i=index;i>=0;i--){//依次进位,知道不能操作
ch[i]=ch[i]+b,b=0;
if(i==0&&ch[i]-'0'>=5&&t) a=1,f=i;
if(i!=0){
if(ch[i]-'0'>=5&&t) b=1,t--,f=i;
else break;
}
}
int flag=0;
if(a){//特判小数点后第一位是否有进位
flag=1;
for(int i=lenn-1;i>=0;i--){
str[i]=str[i]+flag;flag=0;
if(str[i]-'0'>9) str[i]='0',flag=1;
}
}
if(flag) printf("1");
for(int i=0;i