Submission #1078076

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078076		0npata	Fish 2 (JOI22_fish2)	C++17	13 / 100	4090 ms	10864 KiB

fish2

#include<bits/stdc++.h>
using namespace std;


#define vec vector
#define int long long

const int INF = 1e17;

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int N;
    cin >> N;


    vec<int> A(N);
    set<pair<int, int>> A_s;

    for(int i = 0; i<N; i++) {
        cin >> A[i];
        A_s.insert({-A[i], i});
    }

    int Q;
    cin >> Q;
    while(Q--) {
        //cerr << "f" << '\n';
        int T;
        cin  >> T;
        int X, Y;
        cin >> X >> Y;
        X--;
        if(T==1) {
            A_s.erase({-A[X], X});
            A[X] = Y;
            A_s.insert({-Y, X});
            continue;
        }

        vec<int> l(N, -1);
        vec<int> r(N, N);

        vec<pair<int, int>> hi{{INF, -1}};

        for(int i = X; i<Y; i++) {
            while(hi.back().first <= A[i]) {
                hi.pop_back();
                //cerr << "here1" << '\n';
            }
            l[i] = hi.back().second;
            //cerr << l[i] << ' ';
            hi.push_back({A[i], i});
        }
        //cerr << '\n';

        vec<pair<int, int>> hi_r{{INF, N}};

        for(int i = Y-1; i>=X; i--) {
            while(hi_r.back().first <= A[i]) {
                //cerr << "here2" << '\n';
                hi_r.pop_back();
            }
            r[i] = hi_r.back().second;
            hi_r.push_back({A[i], i});
        }
    

        vec<bool> valid(N);
        vec<int> prefixsums(N+2);
        for(int i = 1; i<=N; i++) {
            prefixsums[i] = prefixsums[i-1] + A[i-1];
        }
        prefixsums[N+1] = prefixsums[N];

        //valid[(*A_s.begin()).second] = true;
        int ans = 0;
        for(auto [_, i] : A_s) {
            if(i>=Y || i<X) continue;
            int cl = l[i];
            int cr = r[i];

            int sum = prefixsums[min(cr, Y)]-prefixsums[max(cl+1, X)];

            //cerr << i << ' ' << sum << '\n';

            if(cl != -1) {
                if(sum >= A[cl]) valid[i] = valid[i] | valid[cl];
            }
            if(cr != N) {
                if(sum >= A[cr]) valid[i] = valid[i] | valid[cr];
            }
            if(cl == -1 && cr == N) valid[i] = true;
            //cerr << i << ": " << valid[i] << '\n';
            ans += valid[i];
        }

        cout << ans << '\n';
    }

}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17