POJ 2503-Babelfish Babelfish Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 33433 Accepted: 14347 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 Hint Huge input and output,scanf and printf are recommended. Source Waterloo local 2001.09.22
水题。题目说明了“No foreign word appears more than once in the dictionary”，又要快速查找，马上想到用MAP来当字典，然后查找。这题稍微有点麻烦是的输入输出，因为题目没有给出具体的输入结束标志，需要自己判断，输入的又是字符串，且含有空格空行等，虽然题目hint建议用printf或scanf，但是我选择了用C++的getline，看起来更加优雅。 getline的优点是一次读入一行，不管有没有空格，而且它还能读入空行，所以我们可以使用下面的代码来读取一行并判断跳出循环条件： [cpp] while(getline(cin,s)) { if(s=="") break; } [/cpp] 其他的就是常规的字符串处理，map查找输出。具体代码如下： [cpp] #include<iostream> #include<string> #include<map> #include<vector> using namespace std; int main() { string s; map<string,string> mss; vector<string> vs; while(getline(cin,s)) { if(s=="") break; int blankPos=s.find(" ");//找到空格位置 mss[s.substr(blankPos+1)]=s.substr(0,blankPos);//插入map } while(getline(cin,s)) { if(s=="") break; if(mss.find(s)!=mss.end()) { vs.push_back(mss[s]); //cout<<mss[s]<<endl; } else //cout<<"eh"<<endl; vs.push_back("eh"); } int v_size=vs.size(); for(int i=0;i<v_size;i++) { cout<<vs[i]; if(i!=v_size-1) cout<<endl; } return 0; } [/cpp] 本代码提交AC，用时1000MS，内存14648K，效率比较低，如果使用scanf和printf估计会好些。]]>