1 #include<bits/stdc++.h>
2 using namespace std;
3 const int inf = 0x3f3f3f3f;
4 typedef long long int ll;
5 typedef unsigned long long int ull;
6 const int maxn = 5e6+10;
7 ull hs[maxn];
8 ull base[maxn];
9 char stra[maxn], strb[maxn];
10 int lena,lenb;
11 ull num;
12 char ans[maxn];
13 int main() {
14 while (scanf("%s%s", stra + 1,strb+1) != EOF) {
15 lena = strlen(stra + 1);
16 lenb = strlen(strb + 1);//读入串
17 num = 0;
18 base[0] = 1;
19 for (int i = 1;i < maxn;i++)base[i] = base[i - 1] * 131;
20 for (int i = 1;i <= lena;++i)num = (num * 131) + stra[i] - 'a' + 1;//初始化
21 int pos = 0;
22 for (int i = 1;i <= lenb;++i) {
23 ans[pos++] = strb[i];
24 hs[pos] = hs[pos - 1] * 131 + strb[i] - 'a' + 1;
25 if (pos >= lena && hs[pos] - hs[pos - lena] * base[lena] == num) {//如果长度大于子串就判断，如果等于子串，pos就减掉子串的长度。
26 pos -= lena;
27 }
28 }
29 for (int i = 0;i < pos;i++) printf("%c", ans[i]);
30 puts("");
31 }
32 return 0;
33 }
