20240418

ACMOJ-2122.cpp

@@ -0,0 +1,81 @@
+#include <algorithm>
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+#include <queue>
+using namespace std;
+typedef long long LL;
+typedef long double LDB;
+const int kMaxN = 4e3 + 10;
+struct Point {
+  int a, b, c;
+};
+int ch[2][2][kMaxN][26], fa[2][kMaxN], len[2][kMaxN];
+bool vis[kMaxN][kMaxN];
+int tot[2] = {1, 1}, last[2] = {1, 1};
+char A[kMaxN], B[kMaxN];
+void InitSequenceMachine(char *s, int flag) {
+  for (int i = strlen(s + 1); i; --i) {
+    memcpy(ch[flag][0][i - 1], ch[flag][0][i], 104);
+    ch[flag][0][i - 1][s[i] - 'a'] = i;
+  }
+}
+void AddChar(int character, int string_flag) {
+  int p = last[string_flag], np = last[string_flag] = ++tot[string_flag];
+  len[string_flag][np] = len[string_flag][p] + 1;
+  for (; p && !ch[string_flag][1][p][character]; p = fa[string_flag][p])
+    ch[string_flag][1][p][character] = np;
+  if (!p)
+    fa[string_flag][np] = 1;
+  else {
+    int q = ch[string_flag][1][p][character];
+    if (len[string_flag][q] == len[string_flag][p] + 1)
+      fa[string_flag][np] = q;
+    else {
+      int nq = ++tot[string_flag];
+      len[string_flag][nq] = len[string_flag][p] + 1;
+      fa[string_flag][nq] = fa[string_flag][q];
+      fa[string_flag][q] = fa[string_flag][np] = nq;
+      memcpy(ch[string_flag][1][nq], ch[string_flag][1][q], 104);
+      for (; p && ch[string_flag][1][p][character] == q; p = fa[string_flag][p])
+        ch[string_flag][1][p][character] = nq;
+    }
+  }
+}
+void Solve(int flag1, int flag2) {
+  memset(vis, 0, sizeof(vis));
+  queue<Point> q;
+  q.push((Point){flag1, flag2, 0});
+  vis[flag1][flag2] = 1;
+  while (!q.empty()) {
+    Point now = q.front();
+    q.pop();
+    for (int i = 0; i < 26; ++i)
+      if (ch[0][flag1][now.a][i]) {
+        if (ch[1][flag2][now.b][i]) {
+          int a = ch[0][flag1][now.a][i], b = ch[1][flag2][now.b][i];
+          if (!vis[a][b]) vis[a][b] = 1, q.push((Point){a, b, now.c + 1});
+        } else {
+          printf("%d\n", now.c + 1);
+          return;
+        }
+      }
+  }
+  printf("-1\n");
+}
+int main() {
+#ifdef local
+  freopen("pro.in", "r", stdin);
+#endif
+  scanf("%s", A + 1);
+  scanf("%s", B + 1);
+  InitSequenceMachine(A, 0);
+  InitSequenceMachine(B, 1);
+  for (char *p = A + 1; *p; p++) AddChar(*p - 'a', 0);
+  for (char *p = B + 1; *p; p++) AddChar(*p - 'a', 1);
+  Solve(1, 1);
+  Solve(1, 0);
+  Solve(0, 1);
+  Solve(0, 0);
+  return 0;
+}