1050 String Subtraction(map以及STL的应用)

最新推荐文章于 2021-11-10 21:12:46 发布

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本文详细解析了一种名为字符串减法的算法问题，该问题要求从第一个字符串中移除所有出现在第二个字符串中的字符。文章通过一个具体的代码示例展示了如何使用C++语言实现这一算法，特别关注于如何高效地处理大规模数据输入。示例代码利用了标准模板库中的map容器来标记需要删除的字符，然后遍历第一个字符串，仅保留未被标记的字符。

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1050 String Subtraction （20 分）

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.

#include <iostream>
#include <map>
using namespace std;
map<char,bool> mp;
int main(){
	string s1,s2;
	getline(cin,s1);
	getline(cin,s2);
	for(auto it: s2){
		mp[it]=true;
	}
	for(auto it:s1){
		if(!mp[it]) cout<<it;
	}
	return 0;
}