PAT 1050 String Subtraction

1050 String Subtraction

Given two strings S1​ and S2​, S=S1​−S2​ is defined to be the remaining string after taking all the characters in S2​ from S1​. Your task is simply to calculate S1​−S2​ 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 S1​ and S2​, respectively. The string lengths of both strings are no more than 104. 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 S1​−S2​ in one line.

Sample Input:

They are students.
aeiou

Sample Output:

Thy r stdnts.

总结：这道题还是很简单的，用一个ascii数组标记s2出现过的字符，然后遍历s1字符串，遇到标记过的字符就不打印，反之则打印

#include 
using namespace std;
 
int main(){
    string a,b;
    int ascii[128]={0};
    getline(cin,a);
    getline(cin,b);
    
    for(auto c:b)   ascii[c]=1;
    
    for(auto c:a){
        if(ascii[c])   continue;
        printf("%c",c);
    }
    
    return 0;
}

 好好学习，天天向上！

我要考研！