pat 1050 String Subtraction（20 分）

1050 String Subtraction（20 分）

Given two strings S​1​​ and S​2​​, S=S​1​​−S​2​​ is defined to be the remaining string after taking all the characters in S​2​​ from S​1​​. Your task is simply to calculate S​1​​−S​2​​ for any given strings. However, it might not be that simple to do it fast.

Input Specification:

Each input file contains one test case. Each case consists of two lines which gives S​1​​ and S​2​​, respectively. The string lengths of both strings are no more than 10​4​​. It is guaranteed that all the characters are visible ASCII codes and white space, and a new line character signals the end of a string.

Output Specification:

For each test case, print S​1​​−S​2​​ in one line.

Sample Input:

They are students.

aeiou

Sample Output:

Thy r stdnts.

 #include <iostream>

 #include <algorithm>

 #include <cstdio>

 #include <cstring>

 #include <map>

 #include <stack>

 #include <vector>

 #include <queue>

 #include <set>

 #define LL long long

 using namespace std;

 const int MAX = 1e4 + ;

 string s1, s2;

 int book[MAX] = {}, len1, len2;

 int main()

 {

 //    freopen("Date1.txt", "r", stdin);

     getline(cin, s1);

     getline(cin, s2);

     len1 = s1.size(), len2 = s2.size();

     for (int i = ; i < len2; ++ i) book[s2[i]] = ;

     for (int i = ; i < len1; ++ i)

         if (!book[s1[i]])

             printf("%c", s1[i]);

     return ;

 }