蓝桥杯-阶乘计算

package first_package;

import java.util.List;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.*;
public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner inScanner = new Scanner(System.in);
		int n = inScanner.nextInt();
		List<Integer> result = new ArrayList<Integer>();
		result.add(1);
		int temporary = 0;
		int k = 0;
		for(int i =2;i<=n;i++){
			for(int j =result.size()-1;j>-1;j--){
				k = result.get(j) *i + temporary;
				temporary =  k / 10;
				result.remove(j);
				result.add(j,k  % 10);
			}
			while (temporary >0){
				result.add(0,temporary % 10);
				temporary = temporary/10;
			}
		}
		String str = new String();
		for( int j =0;j<result.size();j++){
			str  = str.concat(String.valueOf(result.get(j)));
		}
		
		
		
		System.out.println(str);
	
	}

}

其余心得

String str1 = String.valueOf(result);

这个语句会将result的结果输出为String。而不是里面的元素。
String.jion()会将Array List或者list的元素合并为String。