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 −S2in one line.
Sample Input:
They are students.
aeiou
Sample Output:
Thy r stdnts.
using namespace std;
#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
int main()
{
int ASCII[200] = {0};//ASCII码一共有一百多个字符
string str1, str2;
getline(cin, str1);
getline(cin, str2);
int len1 = str1.length();
int len2 = str2.length();
for(int i=0; i<len2; i++) ASCII[str2[i]] = 1;//若str2中有字符则将其位置标志置一
for(int i=0; i<len1; i++)
{
if(ASCII[str1[i]]) continue;
printf("%c", str1[i]);//str1中无str2的字符则正常输出即可
}
return 0;
}