P1198 [JSOI2008] 最大数

https://www.luogu.com.cn/record/168534477

Luogu/P1198/P1198.cpp

@@ -1,38 +1,97 @@
-#include <bits/stdc++.h>
+#include <iostream>
 
-using namespace std;
+using std::cin;
+using std::cout;
+const char endl = '\n';
 
-long long t, d, a[200005], f[200005][25];
-int n, m, x;
-char op;
-bool flag;
+const int N = 2e5 + 5;
 
-void change(int u) {
-    f[u][0] = a[u];
-    for (int i = 1; u - (1 << i) >= 0; i++) {
-        f[u][i] = max(f[u][i - 1], f[u - (1 << (i - 1))][i - 1]);
-    }
+int m, d, cnt;
+long long t;
+
+struct node {
+    int l, r;
+    long long max;
+} tr[N << 2];
+
+void pushup(int u) {
+    tr[u].max = std::max(tr[u << 1].max, tr[u << 1 | 1].max);
 }
 
-long long find(int x, int y) {
-    int d = (int)(log(y - x + 1) / log(2));
-    return max(f[y][d], f[x + (1 << d) - 1][d]);
+void build(int u, int l, int r) {
+    tr[u].l = l;
+    tr[u].r = r;
+
+    if (l == r) {
+        tr[u].max = 0;
+
+        return;
+    }
+
+    int mid = (l + r) >> 1;
+
+    build(u << 1, l, mid);          // [l, mid]
+    build(u << 1 | 1, mid + 1, r);  // [mid + 1, r]
+
+    pushup(u);
+}
+
+void modify(int u, int pos, long long val) {
+    if (tr[u].l == pos && tr[u].r == pos) {
+        tr[u].max = val;
+
+        return;
+    }
+
+    int mid = (tr[u].l + tr[u].r) >> 1;
+
+    if (pos <= mid) modify(u << 1, pos, val);
+    else modify(u << 1 | 1, pos, val);
+
+    pushup(u);
+}
+
+long long query(int u, int l, int r) {
+    if (l <= tr[u].l && tr[u].r <= r) return tr[u].max;
+
+    int mid = (tr[u].l + tr[u].r) >> 1;
+    long long res = 0;
+
+    if (l <= mid) res = std::max(res, query(u << 1, l, r));
+    if (r > mid) res = std::max(res, query(u << 1 | 1, l, r));
+
+    return res;
 }
 
 int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(NULL);
+
     cin >> m >> d;
+
+    build(1, 1, m);
+
     while (m--) {
-        cin >> op >> x;
-        if (op == 'A') {
-            a[++n] = (x + t) % d;
-            change(n);
-        } else if (op == 'Q') {
-            if (x == 1) {
-                cout << (t = a[n]) << endl;
-            } else {
-                cout << (t = find(n - x + 1, n)) << endl;
-            }
+        char op;
+
+        cin >> op;
+
+        if (op == 'Q') {
+            int l;
+
+            cin >> l;
+
+            t = query(1, cnt - l + 1, cnt);
+
+            cout << t << endl;
+        } else {  // op == 2
+            long long x;
+
+            cin >> x;
+
+            modify(1, ++cnt, ((t + x) % d + d) % d);
         }
     }
+
     return 0;
 }