题解报告：poj 2503 Babelfish（map）

Posted 2020-12-31 acgoto

Description

You have just moved from Waterloo to a big city. The people here speak an incomprehensible dialect of a foreign language. Fortunately, you have a dictionary to help you understand them.

Input

Input consists of up to 100,000 dictionary entries, followed by a blank line, followed by a message of up to 100,000 words. Each dictionary entry is a line containing an English word, followed by a space and a foreign language word. No foreign word appears more than once in the dictionary. The message is a sequence of words in the foreign language, one word on each line. Each word in the input is a sequence of at most 10 lowercase letters.

Output

Output is the message translated to English, one word per line. Foreign words not in the dictionary should be translated as "eh".

Sample Input

dog ogday
cat atcay
pig igpay
froot ootfray
loops oopslay

atcay
ittenkay
oopslay

Sample Output

cat
eh
loops
解题思路：查字典--->map键值对，由于时间限制，要用C语言的输入输出，因此输入时考虑用sscanf函数来格式化读取的字符串，其他常规处理即可。
int sscanf (const char *str,const char * format,........)；
sscanf函数会将参数str字符串根据参数format字符串来转换并格式化数据，转换后的结果存于对应的参数内。返回值：如果成功，该函数返回成功匹配和赋值的个数。如果到达文件末尾或发生读错误，则返回EOF。
AC代码(2157ms)：

 1 #include<iostream>
 2 #include<map>
 3 #include<string.h>
 4 #include<cstdio>
 5 using namespace std;
 6 const int maxn=30;
 7 char str[maxn],obj[maxn],ans[maxn];
 8 map<string,string> mp;
 9 int main(){
10     while(gets(str)&&strlen(str)){
11         sscanf(str,"%s%s",ans,obj);//格式字符串
12         mp[obj]=ans;//映射（字典）
13     }
14     while(gets(str)){
15         if(mp.find(str)!=mp.end())printf("%s
",mp[str].c_str());
16         else printf("eh
");
17     }
18     return 0;
19 }