Submission #503501

#	Time	Username	Problem	Language	Result	Execution time	Memory
503501		AriaH	Candies (JOI18_candies)	C++17	0 / 100	4 ms	716 KiB

candies

/** I can do this all day **/

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair < int, int > pii;
typedef pair < ll, ll > pll;

#define F first
#define S second
#define all(x) x.begin(), x.end()
#define SZ(x) (int)x.size()
#define Mp make_pair
#define endl "\n"
#define fast_io ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define file_io freopen("inupt.txt", "r+", stdin); freopen("output.txt", "w+", stdout);

const int N = 1e6 + 10;
const ll mod = 1e9 + 7;
const ll inf = 1e18;
const int LOG = 20;

ll pw(ll a, ll b, ll M, ll ret = 1) { if(a == 0) return 0; a %= M; while(b) { ret = (b & 1? ret * a % M : ret), a = a * a % M, b >>= 1; } return ret % M; }

ll ps[N], Ans[N];

int n, ptr, A[N], fen[N];

void add(int i)
{
    for(i += 5; i < N; i += i & -i)
    {
        fen[i] ^= 1;
    }
}

void add(int l, int r)
{
    add(l);
    add(r + 1);
}

int get(int i, int ret = 0)
{
    for(i += 5; i; i -= i & -i) ret ^= fen[i];
    return ret;
}

inline ll Sum(int l, int r)
{
    if(l > r) return 0ll;
    if(r < 0) return 0ll;
    return ps[r] - (l > 1? ps[l - 2] : 0);
}

set < pair < ll, pii > > st;
set < pii > Left, Right;

void Del(int l, int r)
{
    Left.erase(Mp(l, r));
    Right.erase(Mp(r, l));
    st.erase(Mp(-Sum(l, r) + Sum(l + 1, r - 1), Mp(l, r)));
}

int main()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; i ++)
    {
        scanf("%d", &A[i]);
        ps[i] = A[i] + (i > 1? ps[i - 2] : 0);
    }
    ps[n + 1] = ps[n - 1];
    ps[n + 2] = ps[n];
    for(int i = 1; i <= n; i ++)
    {
        st.insert(Mp(-A[i], Mp(i, i)));
        Left.insert(Mp(i, i));
        Right.insert(Mp(i, i));
    }
    ptr = 0;
    while(SZ(st))
    {
        pair < ll, pii > Cu = *st.begin();
        st.erase(st.begin());
        int l = Cu.S.F, r = Cu.S.S;
        Left.erase(Mp(l, r));
        Right.erase(Mp(r, l));
        if(get(l - 1) == 1 || get(r + 1) == 1) continue;
        ptr ++;
        Ans[ptr] = Ans[ptr - 1] + (-Cu.F);
        add(l, r);
        if(get(l - 2))
        {
            pii cu = *Right.lower_bound(Mp(l - 1, -1));
            Del(cu.S, cu.F);
            l = cu.S;
        }
        else
        {
            l --;
        }
        if(get(r + 2))
        {
            pii cu = *Left.lower_bound(Mp(r + 1, -1));
            ///printf("im here cu = %d %d\n", cu.F, cu.S);
            Del(cu.F, cu.S);
            r = cu.S;
        }
        else
        {
            r ++;
        }
        if(l >= 1 && r <= n)
        {
            if(Left.find(Mp(l, l)) != Left.end())
            {
                Del(l, l);
            }
            if(Right.find(Mp(r, r)) != Right.end())
            {
                Del(r, r);
            }
            ///printf("adding %d %d\n", l, r);
            st.insert(Mp(-Sum(l, r) + Sum(l + 1, r - 1), Mp(l, r)));
            Right.insert(Mp(r, l));
            Left.insert(Mp(l, r));
        }
    }
    for(int i = 1; i <= (n + 1) >> 1; i ++)
    {
        printf("%lld\n", Ans[i]);
    }
	return 0;
}

/** test corner cases(n = 1?) watch for overflow or minus indices **/

Compilation message (stderr)

candies.cpp: In function 'int main()':
candies.cpp:72:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
candies.cpp:75:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         scanf("%d", &A[i]);
      |         ~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 92