Init

ACMOJ-2031.cpp

@@ -0,0 +1,153 @@
+#include <algorithm>
+#include <cstdio>
+#include <cstring>
+using namespace std;
+typedef long long LL;
+const int L_TYPE = 0;
+const int S_TYPE = 1;
+namespace __SA_IS {
+int a[2000100], sa[2000100], typ[2000100], c[1000100], p[2000100],
+    sbuc[1000100], lbuc[1000100], name[1000100];
+
+inline int islms(int *typ, int i) { return !typ[i] && (i == 1 || typ[i - 1]); }
+
+int cmp(int *s, int *typ, int p, int q) {
+  do {
+    if (s[p] != s[q]) return 1;
+    p++;
+    q++;
+  } while (!islms(typ, p) && !islms(typ, q));
+  return (!islms(typ, p) || !islms(typ, q) || s[p] != s[q]);
+}
+
+void isort(int *s, int *sa, int *typ, int *c, int n, int m) {
+  int i;
+  for (lbuc[0] = sbuc[0] = c[0], i = 1; i <= m; i++) {
+    lbuc[i] = c[i - 1] + 1;
+    sbuc[i] = c[i];
+  }
+  for (i = 1; i <= n; i++)
+    if (sa[i] > 1 && typ[sa[i] - 1]) sa[lbuc[s[sa[i] - 1]]++] = sa[i] - 1;
+  for (i = n; i >= 1; i--)
+    if (sa[i] > 1 && !typ[sa[i] - 1]) sa[sbuc[s[sa[i] - 1]]--] = sa[i] - 1;
+}
+
+void build_sa(int *s, int *sa, int *typ, int *c, int *p, int n, int m) {
+  int i;
+  for (i = 0; i <= m; i++) c[i] = 0;
+  for (i = 1; i <= n; i++) c[s[i]]++;
+  for (i = 1; i <= m; i++) c[i] += c[i - 1];
+  typ[n] = 0;
+  for (i = n - 1; i >= 1; i--)
+    if (s[i] < s[i + 1])
+      typ[i] = 0;
+    else if (s[i] > s[i + 1])
+      typ[i] = 1;
+    else
+      typ[i] = typ[i + 1];
+  int cnt = 0;
+  for (i = 1; i <= n; i++)
+    if (!typ[i] && (i == 1 || typ[i - 1])) p[++cnt] = i;
+  for (i = 1; i <= n; i++) sa[i] = 0;
+  for (i = 0; i <= m; i++) sbuc[i] = c[i];
+  for (i = 1; i <= cnt; i++) sa[sbuc[s[p[i]]]--] = p[i];
+  isort(s, sa, typ, c, n, m);
+  int last = 0, t = -1, x;
+  for (i = 1; i <= n; i++) {
+    x = sa[i];
+    if (!typ[x] && (x == 1 || typ[x - 1])) {
+      if (!last || cmp(s, typ, x, last))
+        name[x] = ++t;
+      else
+        name[x] = t;
+      last = x;
+    }
+  }
+  for (i = 1; i <= cnt; i++) s[n + i] = name[p[i]];
+  if (t < cnt - 1)
+    build_sa(s + n, sa + n, typ + n, c + m + 1, p + n, cnt, t);
+  else
+    for (i = 1; i <= cnt; i++) sa[n + s[n + i] + 1] = i;
+  for (i = 0; i <= m; i++) sbuc[i] = c[i];
+  for (i = 1; i <= n; i++) sa[i] = 0;
+  for (i = cnt; i >= 1; i--) sa[sbuc[s[p[sa[n + i]]]]--] = p[sa[n + i]];
+  isort(s, sa, typ, c, n, m);
+}
+}  // namespace __SA_IS
+void SA_IS(char *s, int n, int *sa, int *rk) {
+  using namespace __SA_IS;
+  for (int i = 1; i <= n; i++) a[i] = s[i];
+  a[++n] = 0;
+  build_sa(a, sa, typ, c, p, n, 256);
+  n--;
+  for (int i = 1; i <= n; i++) sa[i] = sa[i + 1];
+  for (int i = 1; i <= n; i++) rk[sa[i]] = i;
+}
+void computeHeight(char *s, int n, int *sa, int *rk, int *height) {
+  int k = 0;
+  for (int i = 1; i <= n; i++) {
+    if (rk[i] == 1) {
+      height[rk[i]] = 0;
+      continue;
+    }
+    if (k > 0) {
+      k--;
+    }
+    int j = sa[rk[i] - 1];
+    while (i + k <= n && j + k <= n && s[i + k] == s[j + k]) {
+      k++;
+    }
+    height[rk[i]] = k;
+  }
+}
+LL GetPairMin(int *height, int n) {
+  int *index_stack = 1 + new int[n + 10]();
+  index_stack[-1] = 0;
+  int s_cnt = 0;
+  LL res = 0, cur = 0;
+  index_stack[s_cnt++] = 1;
+  for (int i = 2; i <= n; i++) {
+    while (s_cnt > 0 && height[index_stack[s_cnt - 1]] >= height[i]) {
+      s_cnt--;
+      cur -= (index_stack[s_cnt] - index_stack[s_cnt - 1]) *
+             (LL)height[index_stack[s_cnt]];
+    }
+    index_stack[s_cnt++] = i;
+    cur += (index_stack[s_cnt - 1] - index_stack[s_cnt - 2]) * (LL)height[i];
+    res += cur;
+  }
+  delete[] (index_stack - 1);
+  return res;
+}
+LL calc(char *s, int n) {
+  int *sa = new int[n << 4]();
+  int *rk = new int[n << 4]();
+  int *height = new int[n << 4]();
+  SA_IS(s, n, sa, rk);
+  computeHeight(s, n, sa, rk, height);
+  LL res = GetPairMin(height, n);
+  delete[] sa;
+  delete[] rk;
+  delete[] height;
+  return res;
+}
+const int maxn = 2e5 + 10;
+char s1[maxn], s2[maxn];
+int main() {
+#ifdef local
+  freopen("pro.in", "r", stdin);
+#endif
+  scanf("%s%s", s1 + 1, s2 + 1);
+  int n1 = strlen(s1 + 1);
+  int n2 = strlen(s2 + 1);
+  char *p = new char[n1 + n2 + 10]();
+  for (int i = 1; i <= n1; i++) p[i] = s1[i];
+  p[n1 + 1] = 'z' + 1;
+  for (int i = 1; i <= n2; i++) p[n1 + 1 + i] = s2[i];
+  LL ans = calc(p, n1 + 1 + n2);
+  ans -= calc(s1, n1);
+  ans -= calc(s2, n2);
+  delete[] p;
+  printf("%lld\n", ans);
+  return 0;
+}