test/library_checker/data_structure/static_rmq.test.cpp

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• Last update: 2024-05-31 18:23:43+09:00
• Problem: https://judge.yosupo.jp/problem/staticrmq

Depends on

• Segment Tree (lib/data_structure/segment_tree.hpp)

Code

#define PROBLEM "https://judge.yosupo.jp/problem/staticrmq"
#include <bits/stdc++.h>
using namespace std;

#include "../../../lib/data_structure/segment_tree.hpp"

const long long INF = 0x1fffffffffffffff;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, q; cin >> n >> q;
    auto fx = [](long long x1, long long x2) -> long long { return min(x1, x2); };
    long long ex = INF;
    SegTree<long long> rmq(n, fx, ex);
    for(int i = 0; i < n; i++){
        int a; cin >> a;
        rmq.update(i, a);
    }
    while(q--){
        int l, r; cin >> l >> r;
        cout << rmq.query(l, r) << "\n";
    }
}

#line 1 "test/library_checker/data_structure/static_rmq.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/staticrmq"
#include <bits/stdc++.h>
using namespace std;

#line 2 "lib/data_structure/segment_tree.hpp"

/**
 * @brief Segment Tree
 * @docs docs/data_structure/segment_tree.md
 */

template <typename T>
struct SegTree{
    using FX = function<T(T, T)>; // T•T -> T となる関数の型
    int n;
    const FX fx;
    const T ex;
    vector<T> dat;

    SegTree(int n_, const FX &fx_, const T &ex_) : n(), fx(fx_), ex(ex_){
        int x = 1;
        while(n_ > x){
            x *= 2;
        }
        n = x;
        dat.resize(n * 2);
        for(int i = 0; i < n * 2; ++i){
            dat[i] = ex;
        }
    }
    SegTree(vector<T> &v, const FX &fx_, const T &ex_) : n(), fx(fx_), ex(ex_){
        int x = 1;
        while((int) v.size() > x){
            x *= 2;
        }
        n = x;
        dat.resize(n * 2);
        for(int i = 0; i < n; ++i){
            set(i, (i < (int) v.size() ? v[i] : ex));
        }
        build();
    }

    void set(int i, const T &x){ dat[i + n] = x; }

    void build(){
        for(int k = n - 1; k >= 1; k--) dat[k] = fx(dat[k * 2], dat[k * 2 + 1]);
    }

    T get(int i) const {
        return dat[i + n];
    }

    void update(int i, const T &x){
        i += n;
        dat[i] = x;
        while(i > 0){
            i >>= 1;  // parent
            dat[i] = fx(dat[i * 2], dat[i * 2 + 1]);
        }
    }

    T query(int a, int b){
        T vl = ex;
        T vr = ex;
        int l = a + n;
        int r = b + n;
        while(l < r){
            if(l & 1) vl = fx(vl, dat[l++]);
            if(r & 1) vr = fx(dat[--r], vr);
            l >>= 1;
            r >>= 1;
        }
        return fx(vl, vr);
    }
};
#line 6 "test/library_checker/data_structure/static_rmq.test.cpp"

const long long INF = 0x1fffffffffffffff;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, q; cin >> n >> q;
    auto fx = [](long long x1, long long x2) -> long long { return min(x1, x2); };
    long long ex = INF;
    SegTree<long long> rmq(n, fx, ex);
    for(int i = 0; i < n; i++){
        int a; cin >> a;
        rmq.update(i, a);
    }
    while(q--){
        int l, r; cin >> l >> r;
        cout << rmq.query(l, r) << "\n";
    }
}

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