说说：这道题非常之坑！开始还以为要递归判断的，其实根本不用，只要判断第一层的S即可，其中内嵌的S肯定是正确的。居然还有这样的题目，真的很无语╮(╯_╰)╭
题目：
Secret Research
At a certain laboratory results of secret research are thoroughly encrypted. A result of a single experiment is stored as an information of
实验室关于一些秘密研究成果都是进行完全加密的。实验的结果按照它的完成情况分为：
its completion:
`positive result‘, `negative result‘, `experiment failed‘ or `experiment not completed‘
‘积极结果’，‘消极结果’，‘实验失败’，‘实验未完成’
The encrypted result constitutes a string of digits S, which may take one of the following forms:
加密的结果组成了一个数字串S，它将采用以下的某种形式
positive result S = 1 or S = 4 or S = 78
positive result S = 1 or S = 4 or S = 78 (A sample result S35 means that if we add digits 35 from the right hand side to a digit sequence then we shall get the digit sequence corresponding to a failed experiment)
(如结果S35意思是如果我们把数字35加到一个数字串的右边那么这就是个消极结果（译：原文为实验失败，我认为有误）)
You are to write a program which decrypts given sequences of digits.
你需要写一个程序对数字串进行解密
Input
A integer n stating
the number of encrypted results and then consecutive n lines,
each containing a sequence of digits given as ASCII strings.
整数n代表加密结果的数目，接下来的连续的n行，每行都是用ASCII码表示的数字串
Output
For each analysed sequence of digits the following lines should be sent to output (in separate lines):
分析完数字串后需要输出结果，且一行一个结果
+ for a positive result - for a negative result * for a failed experiment ? for a not completed experiment
In case the analysed string does not determine the experiment result, a first match from the above list should be outputted.
万一数字串并为决定实验结果，输出上表中第一个匹配的项。
Sample Input
4 78 7835 19078 944
Sample Output
+ - ? *
源代码：
#include <stdio.h>
#include <string.h>
int main(){
int N,len;
char S[1000];
//freopen("data.txt","r",stdin);
scanf("%d",&N);
while(N--){
scanf("%s",S);
len=strlen(S);
if(len<=2){//是否为positive
printf("+\n");
continue;
}
if(S[0]=='9'&&S[len-1]=='4'){//是否为failed
printf("*\n");
continue;
}
if(S[len-1]=='5'){//是否为negative
printf("-\n");
continue;
}
printf("?\n");
}
return 0;
}
Secret Research UVA 621