[2019杭电多校第五场][hdu6629]string matching

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<string>
 5 #include<algorithm>
 6 using namespace std;
 7 typedef long long ll;
 8 const int maxn = 1e6 + 10;
 9 int Next[maxn];
10 void getN(char *s1) {//求子串与自身匹配
11     int i = 0, j, p, len = strlen(s1);
12     Next[0] = len;
13     while (i + 1 < len&&s1[i] == s1[i + 1])
14         i++;
15     Next[1] = i;
16     p = 1;
17     for (i = 2; i < len; i++) {
18         if (Next[i - p] + i < Next[p] + p)
19             Next[i] = Next[i - p];
20         else {
21             j = Next[p] + p - i;
22             if (j < 0)
23                 j = 0;
24             while (i + j < len&&s1[j] == s1[i + j])
25                 j++;
26             Next[i] = j;
27             p = i;
28         }
29     }
30 }
31 char s[maxn];
32 int main() {
33     int t;
34     scanf("%d", &t);
35     while (t--) {
36         scanf("%s", s);
37         int n = strlen(s);
38         getN(s);
39         long long ans = 0;
40         for (int i = 1; i < n; ++i) {
41             if (Next[i] == n - i) ans += n - i;
42             else ans += Next[i] + 1;
43         }
44         printf("%lld\n", ans);
45 
46     }
47 }