奇安信816笔试（本菜醉了）
第一题
题目描述有点迷，反复调试都是0，一看AC竟然是三步问题？？！
原提交代码（通过0）：
public static int CalulateMethodCount (int num_money) {
int dp[] = new int[num_money+1];
if(num_money<=0) return 0;
dp[0]=0;
dp[1]=1;
for (int i = 1; i <num_money; i++) {
int k = 0,count=0;
while(count<=i){
k+=dp[count];
count++;
}
dp[i+1]=k+1;
}
return dp[num_money];
//甚至可以直接一行：
//return 1<<(num_money-1);
} 第二题 啊，用例考虑有问题，这是我提交的，只有0.4┭┮﹏┭┮
import java.util.Scanner;
import java.util.Stack;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String s = scanner.nextLine();
s=s.replaceAll("\\t"," ");
//s=s.replaceAll("\\s{1,}"," ");
String [] strings = s.split(" ");
Stack<String> stack = new Stack<>();
Stack<String> undo = new Stack<>();
for(String string :strings){
if(string.equals("undo") && !stack.empty()){
undo.push(stack.pop());
} else if (string.equals("redo") && !undo.empty()) {
stack.push(undo.pop());
}
else{
stack.push(string);
}
}
Stack<String> res = new Stack<>();
while(!stack.empty()){
res.push(stack.pop());
}
StringBuffer sb = new StringBuffer();
while (!res.empty()){
sb.append(res.pop()+" ");
}
String resString = sb.toString();
System.out.println(resString.trim());
}
}
