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https://git.sb/baoshuo/OI-codes.git
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110 lines
2.7 KiB
C++
110 lines
2.7 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;
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double s, s2, d;
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node() {
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l = r = 0;
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s = s2 = d = 0.00;
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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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s = s2 = d = 0.00;
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}
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} tr[100005 << 2];
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int n, m, op, x, y;
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double k, a[100005];
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void pushup(int u) {
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tr[u].s = tr[u << 1].s + tr[u << 1 | 1].s;
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tr[u].s2 = tr[u << 1].s2 + tr[u << 1 | 1].s2;
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}
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void pushdown(int u) {
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if (!tr[u].d) return;
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tr[u << 1].d += tr[u].d;
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tr[u << 1 | 1].d += tr[u].d;
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tr[u << 1].s2 += tr[u << 1].s * tr[u].d * 2 + (tr[u << 1].r - tr[u << 1].l + 1) * tr[u].d * tr[u].d;
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tr[u << 1 | 1].s2 += tr[u << 1 | 1].s * tr[u].d * 2 + (tr[u << 1 | 1].r - tr[u << 1 | 1].l + 1) * tr[u].d * tr[u].d;
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tr[u << 1].s += (tr[u << 1].r - tr[u << 1].l + 1) * tr[u].d;
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tr[u << 1 | 1].s += (tr[u << 1 | 1].r - tr[u << 1 | 1].l + 1) * tr[u].d;
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tr[u].d = 0;
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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].s = a[l];
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tr[u].s2 = a[l] * a[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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double query(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].s;
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}
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int mid = tr[u].l + tr[u].r >> 1;
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double s = 0.00;
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pushdown(u);
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if (l <= mid) s += query(u << 1, l, r);
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if (r > mid) s += query(u << 1 | 1, l, r);
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return s;
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}
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double query2(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].s2;
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}
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int mid = tr[u].l + tr[u].r >> 1;
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double s = 0.00;
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pushdown(u);
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if (l <= mid) s += query2(u << 1, l, r);
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if (r > mid) s += query2(u << 1 | 1, l, r);
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return s;
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}
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void modify(int u, int l, int r, double d) {
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if (l <= tr[u].l && tr[u].r <= r) {
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tr[u].d += d;
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tr[u].s2 += tr[u].s * d * 2 + (tr[u].r - tr[u].l + 1) * d * d;
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tr[u].s += (tr[u].r - tr[u].l + 1) * d;
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return;
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}
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int mid = tr[u].l + tr[u].r >> 1;
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pushdown(u);
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if (l <= mid) modify(u << 1, l, r, d);
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if (r > mid) modify(u << 1 | 1, l, r, d);
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pushup(u);
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}
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int main() {
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cin >> n >> m;
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for (int i = 1; i <= n; i++) {
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cin >> a[i];
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}
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build(1, 1, n);
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for (int i = 0; i < m; i++) {
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cin >> op >> x >> y;
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if (op == 1) {
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cin >> k;
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modify(1, x, y, k);
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} else if (op == 2) {
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cout << fixed << setprecision(4) << (double)query(1, x, y) / (y - x + 1) << endl;
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} else if (op == 3) {
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cout << fixed << setprecision(4) << (double)(query2(1, x, y) / ((y - x + 1) * 1.00)) - pow(query(1, x, y) / ((y - x + 1) * 1.00), 2) << endl;
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}
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}
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return 0;
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}
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