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OI-codes/Luogu/P1083/P1083.cpp
2021-12-01 19:46:42 +08:00

94 lines
2.0 KiB
C++

#include <bits/stdc++.h>
using std::cin;
using std::cout;
using std::endl;
int n, m, d, s, t, a[1000005];
// Segment Tree
void pushup(int);
void pushdown(int);
void build(int, int, int);
void modify(int, int, int, int);
int query(int, int, int);
int main() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
build(1, 1, n);
for (int i = 1; i <= m; i++) {
cin >> d >> s >> t;
if (query(1, s, t) < d) {
cout << -1 << endl
<< i << endl;
exit(0);
} else {
modify(1, s, t, -d);
}
}
cout << 0 << endl;
return 0;
}
// === Segment Tree ===
struct node {
int l, r, m, d;
node()
: l(0), r(0), m(std::numeric_limits<int>::max()), d(0) {}
node(int _l, int _r)
: l(_l), r(_r), m(std::numeric_limits<int>::max()), d(0) {}
} tr[1000005 << 1];
void pushup(int u) {
tr[u].m = std::min(tr[u << 1].m, tr[u << 1 | 1].m);
}
void pushdown(int u) {
auto &root = tr[u], &left = tr[u << 1], &right = tr[u << 1 | 1];
left.m += root.d;
left.d += root.d;
right.m += root.d;
right.d += root.d;
root.d = 0;
}
void build(int u, int l, int r) {
tr[u] = node(l, r);
if (l == r) {
tr[u].m = a[l];
return;
}
int mid = l + r >> 1;
build(u << 1, l, mid);
build(u << 1 | 1, mid + 1, r);
pushup(u);
}
void modify(int u, int l, int r, int k) {
if (l <= tr[u].l && tr[u].r <= r) {
tr[u].m += k;
tr[u].d += k;
return;
}
int mid = tr[u].l + tr[u].r >> 1;
pushdown(u);
if (l <= mid) modify(u << 1, l, r, k);
if (r > mid) modify(u << 1 | 1, l, r, k);
pushup(u);
}
int query(int u, int l, int r) {
if (l <= tr[u].l && tr[u].r <= r) return tr[u].m;
int mid = tr[u].l + tr[u].r >> 1;
int min = std::numeric_limits<int>::max();
pushdown(u);
if (l <= mid) min = std::min(min, query(u << 1, l, r));
if (r > mid) min = std::min(min, query(u << 1 | 1, l, r));
return min;
}