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https://git.sb/baoshuo/OI-codes.git
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75 lines
1.5 KiB
C++
75 lines
1.5 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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struct node {
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int l, r, max, min;
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node() {
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l = r = max = 0;
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min = 0x3f3f3f3f;
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}
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node(int _l, int _r) {
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l = _l;
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r = _r;
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max = 0;
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min = 0x3f3f3f3f;
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}
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} tr[50005 << 2];
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int n, q, a, b, h[50005];
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void pushup(int u) {
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tr[u].max = max(tr[u << 1].max, tr[u << 1 | 1].max);
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tr[u].min = min(tr[u << 1].min, tr[u << 1 | 1].min);
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}
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void build(int u, int l, int r) {
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tr[u] = node(l, r);
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if (l == r) {
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tr[u].max = h[l];
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tr[u].min = h[l];
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return;
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}
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int mid = l + r >> 1;
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build(u << 1, l, mid);
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build(u << 1 | 1, mid + 1, r);
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pushup(u);
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}
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int query_max(int u, int l, int r) {
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if (l <= tr[u].l && tr[u].r <= r) {
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return tr[u].max;
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}
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int mid = tr[u].l + tr[u].r >> 1;
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int s = 0;
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if (l <= mid) s = max(s, query_max(u << 1, l, r));
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if (r > mid) s = max(s, query_max(u << 1 | 1, l, r));
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return s;
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}
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int query_min(int u, int l, int r) {
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if (l <= tr[u].l && tr[u].r <= r) {
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return tr[u].min;
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}
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int mid = tr[u].l + tr[u].r >> 1;
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int s = 0x3f3f3f3f;
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if (l <= mid) s = min(s, query_min(u << 1, l, r));
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if (r > mid) s = min(s, query_min(u << 1 | 1, l, r));
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return s;
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}
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int main() {
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cin >> n >> q;
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for (int i = 1; i <= n; i++) {
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cin >> h[i];
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}
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build(1, 1, n);
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for (int i = 0; i < q; i++) {
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cin >> a >> b;
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cout << query_max(1, a, b) - query_min(1, a, b) << endl;
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}
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return 0;
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}
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