#1602. [Gym102566J] The Sacred Texts

https://sjzezoj.com/submission/58863

S2OJ/1602/1602.cpp

@@ -0,0 +1,162 @@
+#include <iostream>
+#include <algorithm>
+#include <limits>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 15,
+          M = 1e5 + 5;
+
+int n, m, q;
+int cnt, id[N][N];
+long long a[N][M], sum[N][M];
+
+class SegmentTree {
+  private:
+    struct node {
+        int l, r;
+        long long sum, pre, suf, max;
+
+        node(int _l = 0, int _r = 0)
+            : l(_l), r(_r), sum(0), pre(0), suf(0), max(std::numeric_limits<int>::min()) {}
+    } tr[M << 2];
+
+    void pushup(int u) {
+        tr[u].sum = tr[u << 1].sum + tr[u << 1 | 1].sum;
+        tr[u].pre = std::max(tr[u << 1].pre, tr[u << 1].sum + tr[u << 1 | 1].pre);
+        tr[u].suf = std::max(tr[u << 1 | 1].suf, tr[u << 1].suf + tr[u << 1 | 1].sum);
+        tr[u].max = std::max({tr[u << 1].max, tr[u << 1 | 1].max, tr[u << 1].suf + tr[u << 1 | 1].pre});
+    }
+
+    void build(int u, int l, int r, const int& id_l, const int& id_r) {
+        tr[u] = node(l, r);
+
+        if (l == r) {
+            tr[u].sum = tr[u].pre = tr[u].suf = tr[u].max = sum[id_r][l] - sum[id_l - 1][l];
+
+            return;
+        }
+
+        int mid = l + r >> 1;
+
+        build(u << 1, l, mid, id_l, id_r);
+        build(u << 1 | 1, mid + 1, r, id_l, id_r);
+
+        pushup(u);
+    }
+
+    void modify(int u, int p, long long v) {
+        if (tr[u].l == p && tr[u].r == p) {
+            tr[u].sum = tr[u].pre = tr[u].suf = tr[u].max += v;
+
+            return;
+        }
+
+        int mid = tr[u].l + tr[u].r >> 1;
+
+        if (p <= mid) modify(u << 1, p, v);
+        else modify(u << 1 | 1, p, v);
+
+        pushup(u);
+    }
+
+    node query(int u, int l, int r) {
+        if (l <= tr[u].l && tr[u].r <= r) {
+            return tr[u];
+        }
+
+        int mid = tr[u].l + tr[u].r >> 1;
+
+        if (r <= mid) {
+            return query(u << 1, l, r);
+        }
+
+        if (l > mid) {
+            return query(u << 1 | 1, l, r);
+        }
+
+        node res;
+        node left = query(u << 1, l, r);
+        node right = query(u << 1 | 1, l, r);
+
+        res.sum = left.sum + right.sum;
+        res.pre = std::max(left.pre, left.sum + right.pre);
+        res.suf = std::max(left.suf + right.sum, right.suf);
+        res.max = std::max({left.max, right.max, left.suf + right.pre});
+
+        return res;
+    }
+
+  public:
+    void build(int l, int r, int id_l, int id_r) {
+        build(1, l, r, id_l, id_r);
+    }
+
+    void modify(int p, long long v) {
+        modify(1, p, v);
+    }
+
+    node query(int l, int r) {
+        return query(1, l, r);
+    }
+} tr[60];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            cin >> a[i][j];
+
+            sum[i][j] = sum[i - 1][j] + a[i][j];
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = i; j <= n; j++) {
+            tr[id[i][j] = ++cnt].build(1, m, i, j);
+        }
+    }
+
+    cin >> q;
+
+    while (q--) {
+        int op;
+
+        cin >> op;
+
+        if (op == 1) {
+            int x, y, v;
+
+            cin >> x >> y >> v;
+
+            for (int i = 1; i <= x; i++) {
+                for (int j = x; j <= n; j++) {
+                    tr[id[i][j]].modify(y, v - a[x][y]);
+                }
+            }
+
+            a[x][y] = v;
+        } else {  // op == 2
+            int x1, y1, x2, y2;
+            long long res = std::numeric_limits<long long>::min();
+
+            cin >> x1 >> y1 >> x2 >> y2;
+
+            for (int i = x1; i <= x2; i++) {
+                for (int j = i; j <= x2; j++) {
+                    res = std::max(res, tr[id[i][j]].query(y1, y2).max);
+                }
+            }
+
+            cout << res << endl;
+        }
+    }
+
+    return 0;
+}