update

poj/3264.balanced-lineup/main.cc

@@ -0,0 +1,71 @@
+#include <algorithm>
+#include <cstdio>
+
+using namespace std;
+
+const int N = 50000;
+const int INF = 1 << 30;
+
+struct TNode {
+  int min;
+  int max;
+  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->max = -INF;
+  root->min = INF;
+  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 insert(int key, int val) {
+  TNode *root = &tree[0];
+  while (root->beg != root->end) {
+    root->min = min(root->min, val);
+    root->max = max(root->max, val);
+    if (key <= root->mid())
+      root = root->l;
+    else
+      root = root->r;
+  }
+  root->min = val;
+  root->max = val;
+}
+
+pair<int, int> query(TNode *root, int beg, int end) {
+  if (root->beg == beg && root->end == end) return {root->max, root->min};
+  if (root->mid() < beg) return query(root->r, beg, end);
+  if (end <= root->mid()) return query(root->l, beg, end);
+  pair<int, int> pl = query(root->l, beg, root->mid());
+  pair<int, int> pr = query(root->r, root->mid() + 1, end);
+  return {max(pl.first, pr.first), min(pl.second, pr.second)};
+}
+
+int main() {
+  int n, q, h;
+  scanf("%d %d", &n, &q);
+  build_tree(&tree[tid++], 1, n);
+  for (int i = 1; i <= n; i++) {
+    scanf("%d", &h);
+    insert(i, h);
+  }
+  for (int i = 0, s, e; i < q; i++) {
+    scanf("%d %d", &s, &e);
+    pair<int, int> p = query(&tree[0], s, e);
+    printf("%d\n", p.first - p.second);
+  }
+  return 0;
+}