update

poj/3468.a-simple-problem-with-integers/main.cc

@@ -0,0 +1,80 @@
+#include <cstdio>
+
+using namespace std;
+
+const int N = 1000000;
+
+struct TNode {
+  long long val;
+  long long inc;
+  int beg;
+  int end;
+  TNode *l;
+  TNode *r;
+  int mid() { return beg + (end - beg) / 2; }
+};
+
+TNode tree[2 * N];
+int tid = 0;
+
+TNode *build_tree(TNode *root, int beg, int end) {
+  root->beg = beg;
+  root->end = end;
+  root->val = 0;
+  root->inc = 0;
+  if (beg != end) {
+    root->l = build_tree(&tree[tid++], beg, root->mid());
+    root->r = build_tree(&tree[tid++], root->mid() + 1, end);
+  }
+  return root;
+}
+
+void update(TNode *root, int beg, int end, long long inc) {
+  if (root->beg == beg && root->end == end) {
+    root->inc += inc;
+    return;
+  }
+  root->val += inc * (end - beg + 1);
+  if (root->mid() < beg) return update(root->r, beg, end, inc);
+  if (end <= root->mid()) return update(root->l, beg, end, inc);
+  update(root->l, beg, root->mid(), inc);
+  update(root->r, root->mid() + 1, end, inc);
+}
+
+long long query(TNode *root, int beg, int end) {
+  if (beg == root->beg && end == root->end)
+    return root->inc * (end - beg + 1) + root->val;
+  if (root->inc != 0) {
+    root->val += root->inc * (root->end - root->beg + 1);
+    update(root->l, root->beg, root->mid(), root->inc);
+    update(root->r, root->mid() + 1, root->end, root->inc);
+  }
+  root->inc = 0;
+  if (root->mid() < beg) return query(root->r, beg, end);
+  if (end <= root->mid()) return query(root->l, beg, end);
+  return query(root->l, beg, root->mid()) +
+         query(root->r, root->mid() + 1, end);
+}
+
+int main() {
+  int n, q;
+  scanf("%d %d", &n, &q);
+  TNode *root = &tree[tid++];
+  build_tree(root, 1, n);
+  for (int i = 1, v; i <= n; i++) {
+    scanf("%d", &v);
+    update(root, i, i, v);
+  }
+  char op[2];
+  for (int i = 0, a, b, c; i < q; i++) {
+    scanf("%s", op);
+    if (op[0] == 'C') {
+      scanf("%d %d %d", &a, &b, &c);
+      update(root, a, b, c);
+    } else {
+      scanf("%d %d", &a, &b);
+      printf("%lld\n", query(root, a, b));
+    }
+  }
+  return 0;
+}