제출 #985724

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
985724		gggkik	Feast (NOI19_feast)	C++14	71 / 100	126 ms	153120 KiB

feast

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<ll,ll>;
const ll inf = 1e18;
const int MXN = 3e5+5;
struct node{
    pii l, r; // v, pos
    pair<ll,pii> m;
    ll a;
}t[MXN<<2], nt[MXN<<2];
int A[MXN], lz[MXN];
node operator+(const node &i, const node &j){
    node k;
    k.l = max(i.l,{i.a+j.l.first,j.l.second});
    k.r = max(j.r,{i.r.first+j.a,i.r.second});
    k.m = max(i.m,j.m);
    k.m = max(k.m,{i.r.first+j.l.first,{i.r.second,j.l.second}});
    k.a = i.a+j.a;
    return k;
}
void push(int x,int s,int e){
    if(!lz[x]) return;
    swap(t[x],nt[x]);
    if(s!=e){
        lz[x*2] ^= lz[x];
        lz[x*2+1] ^= lz[x];
    }
    lz[x] = 0;
}
void upd(int x,int s,int e,int l,int r){
    push(x,s,e);
    if(e<l || r<s) return;
    if(l<=s && e<=r) {
        lz[x]^=1;
        return push(x,s,e);
    }
    int mid = s+e>>1;
    upd(x*2,s,mid,l,r), upd(x*2+1,mid+1,e,l,r);
    t[x] = t[x*2]+t[x*2+1];
    nt[x] = nt[x*2]+nt[x*2+1];   
}
void init(int x,int s,int e){
    if(s==e) {
        ll v = A[s];
        t[x] = {{v,s},{v,s},{v,{s,s}},v};
        nt[x] = {{-v,s},{-v,s},{-v,{s,s}},-v};
        return;
    }
    int mid = s+e>>1;
    init(x*2,s,mid), init(x*2+1,mid+1,e);
    t[x] = t[x*2]+t[x*2+1];
    nt[x] = nt[x*2]+nt[x*2+1];
}
int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n, k; cin >> n >> k;
    for(int i = 1;i<=n;i++) cin >> A[i];
    init(1,1,n);
    ll ans = 0;
    for(int i = 0;i<k;i++){
        auto [l,r] = t[1].m.second;
        ll v = t[1].m.first;
        if(v<=0) break;
        ans += v;
        upd(1,1,n,l,r);
    }
    cout << ans;
}

컴파일 시 표준 에러 (stderr) 메시지

feast.cpp: In function 'void upd(int, int, int, int, int)':
feast.cpp:38:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   38 |     int mid = s+e>>1;
      |               ~^~
feast.cpp: In function 'void init(int, int, int)':
feast.cpp:50:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   50 |     int mid = s+e>>1;
      |               ~^~
feast.cpp: In function 'int main()':
feast.cpp:62:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   62 |         auto [l,r] = t[1].m.second;
      |              ^

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 0 / 29