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OI-codes/Luogu/P1471/P1471.cpp

110 lines
2.7 KiB
C++

#include <bits/stdc++.h>
using namespace std;
struct node {
int l, r;
double s, s2, d;
node() {
l = r = 0;
s = s2 = d = 0.00;
}
node(int _l, int _r) {
l = _l;
r = _r;
s = s2 = d = 0.00;
}
} tr[100005 << 2];
int n, m, op, x, y;
double k, a[100005];
void pushup(int u) {
tr[u].s = tr[u << 1].s + tr[u << 1 | 1].s;
tr[u].s2 = tr[u << 1].s2 + tr[u << 1 | 1].s2;
}
void pushdown(int u) {
if (!tr[u].d) return;
tr[u << 1].d += tr[u].d;
tr[u << 1 | 1].d += tr[u].d;
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;
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;
tr[u << 1].s += (tr[u << 1].r - tr[u << 1].l + 1) * tr[u].d;
tr[u << 1 | 1].s += (tr[u << 1 | 1].r - tr[u << 1 | 1].l + 1) * tr[u].d;
tr[u].d = 0;
}
void build(int u, int l, int r) {
tr[u] = node(l, r);
if (l == r) {
tr[u].s = a[l];
tr[u].s2 = a[l] * a[l];
return;
}
int mid = l + r >> 1;
build(u << 1, l, mid);
build(u << 1 | 1, mid + 1, r);
pushup(u);
}
double query(int u, int l, int r) {
if (l <= tr[u].l && tr[u].r <= r) {
return tr[u].s;
}
int mid = tr[u].l + tr[u].r >> 1;
double s = 0.00;
pushdown(u);
if (l <= mid) s += query(u << 1, l, r);
if (r > mid) s += query(u << 1 | 1, l, r);
return s;
}
double query2(int u, int l, int r) {
if (l <= tr[u].l && tr[u].r <= r) {
return tr[u].s2;
}
int mid = tr[u].l + tr[u].r >> 1;
double s = 0.00;
pushdown(u);
if (l <= mid) s += query2(u << 1, l, r);
if (r > mid) s += query2(u << 1 | 1, l, r);
return s;
}
void modify(int u, int l, int r, double d) {
if (l <= tr[u].l && tr[u].r <= r) {
tr[u].d += d;
tr[u].s2 += tr[u].s * d * 2 + (tr[u].r - tr[u].l + 1) * d * d;
tr[u].s += (tr[u].r - tr[u].l + 1) * d;
return;
}
int mid = tr[u].l + tr[u].r >> 1;
pushdown(u);
if (l <= mid) modify(u << 1, l, r, d);
if (r > mid) modify(u << 1 | 1, l, r, d);
pushup(u);
}
int main() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
build(1, 1, n);
for (int i = 0; i < m; i++) {
cin >> op >> x >> y;
if (op == 1) {
cin >> k;
modify(1, x, y, k);
} else if (op == 2) {
cout << fixed << setprecision(4) << (double)query(1, x, y) / (y - x + 1) << endl;
} else if (op == 3) {
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;
}
}
return 0;
}