Submission #950976

#	Time	Username	Problem	Language	Result	Execution time	Memory
950976		VinhLuu	Cat Exercise (JOI23_ho_t4)	C++17	41 / 100	100 ms	29264 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define pb push_back
using namespace std;

const int N = 2e5 + 5;

int n, a[N];
vector<int> p[N];

namespace sub3{
    int st[N << 1];
    int get(int l,int r){
        r++;
        int ret = 0;
        for(l += n - 1, r += n - 1; l < r; l /= 2, r /= 2){
            if(l & 1){
                if(a[ret] < a[st[l]]) ret = st[l];
                l++;
            }
            if(r & 1){
                --r;
                if(a[ret] < a[st[r]]) ret = st[r];
            }
        }
        return ret;
    }
    int dq(int l,int r){
        if(l > r) return 0;
        int u = get(l, r);
        int L = (u == l ? 0 : dq(l, u - 1) + u - get(l, u - 1));
        int R = (r == u ? 0 : dq(u + 1, r) + get(u + 1, r) - u);
        return max(L, R);
    }
    void solve(){
        for(int i = 1; i <= n; i ++){
            st[i + n - 1] = i;
        }
        for(int i = n - 1; i >= 1; i --){
            if(a[st[i << 1]] > a[st[i << 1|1]]) st[i] = st[i << 1];
            else st[i] = st[i << 1|1];
        }
        cout << dq(1, n);
    }
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #define task "ce"
    if(fopen(task ".inp","r")){
        freopen(task ".inp","r",stdin);
        freopen(task ".out","w",stdout);
    }
    cin >> n;
    for(int i = 1; i <= n; i ++){
        cin >> a[i];
    }
    bool ff = true;
    for(int i = 1; i < n; i ++){
        int x, y; cin >> x >> y;
        if(y != x + 1) ff = false;
        p[x].pb(y);
        p[y].pb(x);
    }
    if(ff) sub3 :: solve();
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen(task ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(task ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 20 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26