P3809 【模板】后缀排序

https://www.luogu.com.cn/record/76864570

Luogu/P3809/P3809.cpp

@@ -0,0 +1,56 @@
+#include <iostream>
+#include <algorithm>
+#include <array>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e6 + 5;
+
+int n;
+std::string s;
+std::array<int, N> sa;
+std::array<int, N << 1> rk, rk1;
+
+void get_sa() {
+    for (int i = 1; i <= n; i++) {
+        sa[i] = i;
+        rk[i] = s[i];
+    }
+
+    for (int w = 1; w < n; w <<= 1) {
+        std::sort(sa.begin() + 1, sa.begin() + 1 + n, [&](auto x, auto y) {
+            return rk[x] == rk[y] ? rk[x + w] < rk[y + w] : rk[x] < rk[y];
+        });
+
+        rk1 = rk;
+
+        for (int 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;
+            }
+        }
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> s;
+    n = s.size();
+    s = ' ' + s;
+
+    get_sa();
+
+    for (int i = 1; i <= n; i++) {
+        cout << sa[i] << ' ';
+    }
+    cout << endl;
+
+    return 0;
+}