Submission #48412

#	Time	Username	Problem	Language	Result	Execution time	Memory
48412		choikiwon	Candies (JOI18_candies)	C++17	100 / 100	146 ms	65368 KiB

candies

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

typedef long long ll;
typedef pair<int, int> pii;

const int MN = 200010;

int N;
ll A[MN];
int pre[MN], nxt[MN];
priority_queue<pair<ll, int> > pq;

int main() {
    scanf("%d", &N);

    for(int i = 0; i < N; i++) {
        scanf("%lld", &A[i]);
    }
    for(int i = 0; i < N; i++) {
        pre[i] = i - 1;
        nxt[i] = i + 1;
        pq.push({ A[i], i });
    }

    ll sum = 0;
    for(int i = 1; i <= (N + 1) / 2; i++) {
        pair<ll, int> t = {-1, -1};
        while(!pq.empty()) {
            t = pq.top(); pq.pop();
            if(A[t.second] == t.first) break;
        }
        sum += t.first;
        printf("%lld\n", sum);

        A[t.second] = -A[t.second];
        bool ok = true;
        if(pre[t.second] != -1) {
            A[t.second] += A[ pre[t.second] ];
            A[ pre[t.second] ] = -1e18;
            pre[t.second] = pre[ pre[t.second] ];
            if(pre[t.second] != -1) nxt[ pre[t.second] ] = t.second;
        }
        else ok = false;
        if(nxt[t.second] != N) {
            A[t.second] += A[ nxt[t.second] ];
            A[ nxt[t.second] ] = -1e18;
            nxt[t.second] = nxt[ nxt[t.second] ];
            if(nxt[t.second] != N) pre[ nxt[t.second] ] = t.second;
        }
        else ok = false;
        if(ok) pq.push({ A[t.second], t.second });
        else A[t.second] = -1e18;
    }
}

Compilation message (stderr)

candies.cpp: In function 'int main()':
candies.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
candies.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld", &A[i]);
         ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 92 / 92