2715. 后缀数组

AcWing/2715/2715.cpp

@@ -0,0 +1,86 @@
+#pragma GCC optimize("O3,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+#include <iostream>
+#include <array>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e6 + 5;
+
+int n, m, cnt[N], id[N], px[N], sa[N], height[N];
+std::string s;
+std::array<int, N> rk, rk1;
+
+void get_sa() {
+    for (int i = 1; i <= n; i++) ++cnt[rk[i] = s[i]];
+    for (int i = 1; i <= m; i++) cnt[i] += cnt[i - 1];
+    for (int i = n; i; i--) sa[cnt[rk[i]]--] = i;
+
+    for (int w = 1, p = 0, i;; w <<= 1, m = p) {
+        for (i = n, p = 0; i > n - w; i--) id[++p] = i;
+        for (int i = 1; i <= n; i++) {
+            if (sa[i] > w) id[++p] = sa[i] - w;
+        }
+
+        std::fill(cnt, cnt + 1 + m, 0);
+
+        for (int i = 1; i <= n; i++) ++cnt[px[i] = rk[id[i]]];
+        for (int i = 1; i <= m; i++) cnt[i] += cnt[i - 1];
+        for (int i = n; i; i--) sa[cnt[px[i]]--] = id[i];
+
+        rk1 = rk;
+        for (i = 1, p = 0; i <= n; i++) {
+            if (rk1[sa[i]] == rk1[sa[i - 1]] && rk1[sa[i] + w] == rk1[sa[i - 1] + w]) {
+                rk[sa[i]] = p;
+            } else {
+                rk[sa[i]] = ++p;
+            }
+        }
+
+        if (p == n) {
+            for (int i = 1; i <= n; i++) sa[rk[i]] = i;
+
+            break;
+        }
+    }
+}
+
+void get_height() {
+    for (int i = 1, k = 0; i <= n; i++) {
+        if (!rk[i]) continue;
+        if (k) k--;
+
+        while (s[i + k] == s[sa[rk[i] - 1] + k]) k++;
+
+        height[rk[i]] = k;
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> s;
+    n = s.size();
+    m = 300;
+    s = ' ' + s;
+
+    get_sa();
+    get_height();
+
+    for (int i = 1; i <= n; i++) {
+        cout << sa[i] << ' ';
+    }
+    cout << endl;
+
+    for (int i = 1; i <= n; i++) {
+        cout << height[i] << ' ';
+    }
+    cout << endl;
+
+    return 0;
+}