'commit'

TangDou/AcWing/Trie/256.cpp

@@ -0,0 +1,70 @@
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+const int N = 6e5 + 10, M = 25 * N;
+int s[N];
+int tr[M][2], ver[M];
+int root[N], idx;
+
+void insert(int k, int p, int q) {
+    for (int i = 23; ~i; i--) {
+        int u = s[k] >> i & 1;
+        tr[q][u ^ 1] = tr[p][u ^ 1]; //复制
+        tr[q][u] = ++idx;            //创建
+        ver[tr[q][u]] = k;           //记录版本
+        q = tr[q][u], p = tr[p][u];
+    }
+}
+
+int query(int p, int l, int c) {
+    for (int i = 23; ~i ; i--) {
+        int u = c >> i & 1;
+        if (tr[p][u ^ 1] && ver[tr[p][u ^ 1]] >= l)
+            p = tr[p][u ^ 1];
+        else
+            p = tr[p][u];
+    }
+    return c ^ s[ver[p]]; // p:最终停留在的异或和最大值终点处,ver[p]这是哪个版本放进来的？,s[ver[p]]=S_{p-1}
+}
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(0);
+    int n, m;
+    cin >> n >> m;
+
+    // 0号版本,用于处理类似于S[1]-S[0]这样的递推边界值
+    root[0] = ++idx;
+    insert(0, 0, root[0]);
+
+    for (int i = 1; i <= n; i++) {
+        int x;
+        cin >> x;
+        root[i] = ++idx;
+        s[i] = s[i - 1] ^ x; //原数组不重要，异或前缀和数组才重要
+        insert(i, root[i - 1], root[i]);
+    }
+
+    while (m--) {
+        char op;
+        cin >> op;
+        if (op == 'A') {
+            int x;
+            cin >> x;
+            n++;
+
+            root[n] = ++idx;
+            s[n] = s[n - 1] ^ x;
+            insert(n, root[n - 1], root[n]);
+        } else {
+            int l, r, x;
+            cin >> l >> r >> x;
+            printf("%d\n", query(root[r - 1], l - 1, s[n] ^ x));
+        }
+    }
+    return 0;
+}