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OI-codes/Luogu/P8251/P8251.cpp

93 lines
1.7 KiB
C++

#include <iostream>
#include <stack>
#include <vector>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 5e5 + 5;
struct node {
int a, b, idx;
node()
: a(0),
b(0),
idx(0) {}
node(int _a, int _b, int _idx)
: a(_a),
b(_b),
idx(_idx) {}
};
int n, q, a[N], b[N], id[N], t[N], ans[N];
std::stack<node> st;
std::vector<int> aa[N], bb[N];
std::pair<int, int> qq[N];
int lowbit(int x) {
return x & (-x);
}
void add(int x) {
for (; x <= n; x += lowbit(x))
t[x]++;
}
int ask(int x) {
int ans = 0;
for (; x; x -= lowbit(x))
ans += t[x];
return ans;
}
inline int sum(int x, int y) {
return ask(y) - ask(x - 1);
}
int main() {
std::ios::sync_with_stdio(false);
cin >> n >> q;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
for (int i = 1; i <= n; i++) {
cin >> b[i];
}
st.push(node(-1, 0, 0));
for (int i = 1; i <= n; i++) {
while (!st.empty() && (st.top().a == a[i] || st.top().b <= b[i])) st.pop();
if (!st.empty()) id[i] = st.top().idx;
st.push(node(a[i], b[i], i));
}
for (int i = 1; i <= n; i++) {
aa[id[i]].push_back(i);
}
for (int i = 1; i <= q; i++) {
cin >> qq[i].first >> qq[i].second;
bb[qq[i].first].push_back(i);
}
for (int i = 1; i <= n; i++) {
for (int k = 0; k < aa[i - 1].size(); k++) {
add(aa[i - 1][k]);
}
for (int t : bb[i]) {
int l = qq[t].first,
r = qq[t].second;
ans[t] = sum(l, r);
}
}
for (int i = 1; i <= q; i++) {
cout << ans[i] << endl;
}
return 0;
}