1050 String Subtraction

Statement

Metadata

作者: CHEN, Yue
单位: 浙江大学
代码长度限制: 16 KB
时间限制: 100 ms
内存限制: 64 MB

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.

Solution

C++

#include <bits/stdc++.h>
using namespace std;
int main() {
    string s1, s2;
    getline(cin, s1);
    getline(cin, s2);
    map<char, int> p;
    int len1 = s1.size(), len2 = s2.size(), i;
    for (i = 0; i < len2; i++) p[s2[i]] = 1;
    for (i = 0; i < len1; i++) {
        if (!p[s1[i]])
            cout << s1[i];
    }
    cout << endl;
}

Last update: May 4, 2022