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LST_RMQ_RUQ.cpp
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LST_RMQ_RUQ.cpp
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#include <iostream>
#include <vector>
using namespace std;
using ll = long long;
class LST_RMQ_RUQ {
private:
int n;
vector<ll> node, lazy;
public:
const ll INF = 1LL << 60;
LST_RMQ_RUQ(int N) {
n = 1;
while (n < N) n *= 2;
node.assign(2*n - 1, INF);
lazy.assign(2*n - 1, INF);
}
// set and build
LST_RMQ_RUQ(vector<ll>& V) {
int sz = V.size();
n = 1;
while (n < sz) n *= 2;
node.assign(2*n - 1, INF);
lazy.assign(2*n - 1, INF);
for (int i = 0; i < sz; ++i) node[n-1+i] = V[i];
for (int i = n-2; i >= 0; --i) node[i] = min(node[2*i+1], node[2*i+2]);
}
void eval(int k) {
/** INFで更新するときはINF-1とするなど注意が必要 **/
if (lazy[k] == INF) return;
if (k < n - 1) {
lazy[k*2+1] = lazy[k];
lazy[k*2+2] = lazy[k];
}
node[k] = lazy[k];
lazy[k] = INF;
}
// RUQ // 区間[a, b)
// if you want to update a node you can call this like (a, a+1, x)
void update(int a, int b, ll x, int k=0, int l=0, int r =-1) {
if (r < 0) r = n;
eval(k);
if (r <= a || b <= l) return;
if (a <= l && r <= b) {
lazy[k] = x;
eval(k);
return;
}
update(a, b, x, k*2+1, l, (l+r)/2);
update(a, b, x, k*2+2, (l+r)/2, r);
node[k] = min(node[k*2+1], node[k*2+2]);
}
// RMQ
ll query(int a=0, int b=-1, int k=0, int l=0, int r=-1) {
if (r < 0) r = n;
if (b < 0) b = n;
eval(k);
if (r <= a || b <= l) return INF;
if (a <= l && r <= b) return node[k];
ll vl = query(a, b, k*2+1, l, (l+r)/2);
ll vr = query(a, b, k*2+2, (l+r)/2, r);
return min(vl, vr);
}
/**
* 二分探索を追加する, より深く理解する
* https://algo-logic.info/segment-tree/
*/
};
// 複数updateする場合は遅延評価が必要だが、一つなら遅延評価はいらないので、普通のセグ木で良い
// 最初はINFのみ、vectorを渡してはいけない、最初だけは評価がされないので
// [l, r)
class ST_RMQ_RUQ {
private:
int n;
vector<ll> node;
public:
const long long INF = 1LL << 60;
ST_RMQ_RUQ(int N) {
n = 1;
while(n < N) n *= 2;
node.assign(2*n-1, INF);
}
void update(int i, ll x) {
i += n-1;
node[i] = x;
while (i > 0) {
i = (i-1) / 2;
node[i] = min(node[i*2+1], node[i*2+2]);
}
}
ll query(int a=0, int b=-1, int k=0, int l=0, int r=-1) {
if (r < 0) r = n;
if (b < 0) b = n;
if (r <= a || b <= l) return INF;
if (a <= l && r <= b) return node[k];
ll vl = query(a, b, k*2+1, l, (l+r)/2);
ll vr = query(a, b, k*2+2, (l+r)/2, r);
return min(vl, vr);
}
void print() {
for (int i = 0; i < 5; ++i) cout << node[i] << " ";
cout << endl;
}
};