HDU 6629 string matching (expand kmp)

http://acm.hdu.edu.cn/showproblem.php?pid=6629

Board questions

 1 #define bug(x) cout<<#x<<" is "<<x<<endl
 2 #define IO std::ios::sync_with_stdio(0)
 3 #include <bits/stdc++.h>
 4 #define iter ::iterator
 5 using namespace  std;
 6 typedef long long ll;
 7 typedef pair<ll,ll>P;
 8 typedef pair<P,P>P1;
 9 #define mk make_pair
10 #define pb push_back
11 #define se second
12 #define fi first
13 #define rs o<<1|1
14 #define ls o<<1
15 const int N=1e6+5;
16 ll mod=998244353;
17 int T,n;
18 int next1[N],ex[N];
19 
20 void GETNEXT(char *str)
21 {
22     int i=0,j,po,len=strlen(str);
23     next1[0]=len;//初始化next[0]
24     while(str[i]==str[i+1]&&i+1<len)// Calculation Next [. 1] 
25          I ++ ;
 26 is      the Next1 [ . 1 ] = I;
 27      po = . 1 ; // position initialization po of 
28      for (I = 2 ; I <len; I ++ )
 29      {
 30          IF (the Next1 [I -PO] + I <the Next1 [PO] + PO) // first case, the value can be obtained directly next [i] of 
31 is              the Next1 [I] = the Next1 [I- PO];
 32          the else // second case , continue to match to get next [i] value 
33 is          {
 34 is              J = the Next1 [PO] + weight PO- I;
 35              IF (J <0 ) J = 0 ; // if i> po + next [po] , will have to start from scratch match 
36              the while (I + J <len && STR [J] == STR [J + I]) // calculate next [i] 
37 [                  J ++ ;
 38 is              the Next1 [I] = J;
 39              po = I; // update location of po 
40          }
 41      }
 42  }
 43  // calculate extend array 
44 is  void EXKMP ( char * S1, char * S2)
 45  {
 46 is      int = I 0 , J, PO, len = strlen (S1), L2 =strlen (S2);
 47      GETNEXT (S2); // calculate substring next array 
48      the while (S1 [I] == S2 [I] && I <L2 && I <len) // calculate EX [0] 
49          I ++ ;
 50      EX [ 0 ] = I;
 51 is      po = 0 ; // initialize po position 
52 is      for (I = . 1 ; I <len; I ++ )
 53 is      {
 54 is          IF (the Next1 [I-po] + I <EX [po] + po ) // first case, the value can be obtained directly ex [i] of 
55              ex [i] = the Next1 [I- PO];
 56 is          the else // second case, to continue to match the values obtained ex [i] of
57 is          {
 58              J = EX [PO] + weight PO- I;
 59              IF (J < 0 ) = J 0 ; // if i> ex [po] + po scratch will have matching 
60              the while (I + J <len && J < L2 && S1 [J + I] == S2 [J]) // calculate EX [I] 
61 is                  J ++ ;
 62 is              EX [I] = J;
 63 is              po = I; // update po position 
64          }
 65      }
 66  }
 67  
68  char S [N];
 69  int main () {
 70      Scanf ( "%d",&T);
71     while(T--){
72         scanf("%s",s);
73         //getNext(s);
74         EXKMP(s,s);
75         int len=strlen(s);
76         ll ans=0;
77         for(int i=1;i<len;i++){
78             //bug(extend[i]);
79             ans+=ex[i]+1;
80             if(ex[i]+i>=len)ans--;
81         }
82         printf("%lld\n",ans);
83         for(int i=0;i<=len+2;i++){
84             next1[i]=ex[i]=0;
85         }
86     }
87 }