Ultraviolet A 1449-Dominating Patterns (AC automatic mechanism)

Ultraviolet A 1449-Dominating Patterns (AC automatic mechanism)

Exercise level: Ultraviolet A 1449-Dominating Patterns

There is a string composed of lowercase letters and a text T, which requires that the strings appear in the text most often.

Solution: Establish an AC automatic machine for the string set, pass in T for matching, add 1 to the number of times that each string matches, and finally find the maximum value. String output with the same number of occurrences as the maximum value. Note that the character set contains the same characters.

#include 
  
   #include 
   
    #include 
    
     #include 
     
      #include
      #include using namespace std;const int maxn = 155;const int maxl = 100;const int maxt = 1e6+5;const int sigma_size = 26;const int noden = maxn * maxl;char str[maxt], word[maxn][maxl];map
       
         ms;int N, c[maxn];int sz, ac[noden][sigma_size], val[noden];int fail[noden], last[noden];void insert (int x, char* s) { int u = 0, n = strlen(s); for (int i = 0; i < n; i++) { int v = s[i] - 'a'; if (ac[u][v] == 0) { memset(ac[sz], 0, sizeof(ac[sz])); val[sz] = 0; ac[u][v] = sz++; } u = ac[u][v]; } val[u] = x;}void get_fail () { queue
        
          que; fail[0] = 0; for (int i = 0; i < sigma_size; i++) { int u = ac[0][i]; if (u) { fail[u] = last[u] = 0; que.push(u); } } while (!que.empty()) { int r = que.front(); que.pop(); for (int i = 0; i < sigma_size; i++) { int u = ac[r][i]; if (u == 0) { ac[r][i] = ac[fail[r]][i]; continue; } que.push(u); int v = fail[r]; while (v && !ac[v][i]) v = fail[v]; fail[u] = ac[v][i]; last[u] = val[fail[u]] ? fail[u] : last[fail[u]]; } }}void count (int x) { if (x) { c[val[x]]++; count(last[x]); }}void find (char* T) { int u = 0; int n = strlen(T); for (int i = 0; i < n; i++) { int v = T[i] - 'a'; /* while (u && !ac[u][v]) u = fail[u]; */ u = ac[u][v]; if (val[u]) count(u); else count(last[u]); }}void init () { sz = 1; ms.clear(); memset(ac[0], 0, sizeof(ac[0])); for (int i = 1; i <= N; i++) { scanf("%s", word[i]); insert(i, word[i]); ms[string(word[i])] = i; } memset(c, 0, sizeof(c)); get_fail();}int main () { while (scanf("%d", &N) == 1 && N) { init(); scanf("%s", str); find(str); int ans = -1; for (int i = 1; i <= N; i++) ans = max(ans, c[i]); printf("%d\n", ans); for (int i = 1; i <= N; i++) { if (c[ms[string(word[i])]] == ans) printf("%s\n", word[i]); } } return 0;}