Train Problem II
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 12896 Accepted Submission(s): 6868
Problem DescriptionAs we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway.InputThe input contains several test cases. Each test cases consists of a number N(1<=N<=100). The input is terminated by the end of file.OutputFor each test case, you should output how many ways that all the trains can get out of the railway.Sample Input1 2 3 10Sample Output1 2 5 16796HintThe result will be very large, so you may not process it by 32-bit integers.AuthorIgnatius.LRecommend
典型卡特蘭數模板題,大數打表
公式:
import java.io.*;
import java.math.*;
import java.util.*;
public class Main {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
BigInteger s[] = new BigInteger[105];
s[1] = BigInteger.ONE;
for(int i = 2;i < 105;i ++){
s[i] = s[i-1].multiply(BigInteger.valueOf(4 * i - 2)).divide(BigInteger.valueOf(i + 1));
}
while(sc.hasNext()){
int n = sc.nextInt();
System.out.println(s[n]);
}
}
}