Submission #379631

#	Time	Username	Problem	Language	Result	Execution time	Memory
379631		limabeans	Sjeckanje (COCI21_sjeckanje)	C++17	110 / 110	973 ms	49260 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl
 
 
 
 
 
using ll = long long;
 
 
const int maxn = 2e5+10;
 
 
 
int n,q;
ll a[maxn];
 
 
//00
//01
//10
//11
 
ll sgn(ll x) {
    if (x==0) return 0;
    if (x>0) return 1;
    if (x<0) return -1;
    
    assert(false);
    return 1;
}
 
struct node {
    ll lval, rval;
    ll dp[2][2];
    node() {
	lval = rval = 0;
	memset(dp, 0, sizeof(dp));
    }

    node(ll x) {
	lval = rval = x;
	memset(dp, 0, sizeof(dp));
	dp[1][1] = abs(x);
    }
};
 
void setmax(ll &x, ll y) {
    x = max(x, y);
}
 
node merge(node x, node y) {
    node res;


    // [i,k0] [k1,j]
    for (int i=0; i<2; i++) {
	for (int j=0; j<2; j++) {
	    for (int k0=0; k0<2; k0++) {
		for (int k1=0; k1<2; k1++) {
		    bool mergable = true;
		    if (k0==1 && k1==1) {
			if (sgn(x.rval)*sgn(y.lval) == -1) {
			    mergable = false;
			}
		    }
		    
		    if (mergable) {
			setmax(res.dp[i][j], x.dp[i][k0]+y.dp[k1][j]);
		    }
		}
	    }
	}
    }

    res.lval = x.lval;
    res.rval = y.rval;

    return res;
}
 
node t[4*maxn];
 
void upd(int v, int tl, int tr, int i, ll dx) {
    if (tl==tr) {
	ll prev = t[v].lval;
	t[v] = node(prev+dx);
    } else {
	int tm=(tl+tr)/2;
	if (i<=tm) {
	    upd(2*v,tl,tm,i,dx);
	} else {
	    upd(2*v+1,tm+1,tr,i,dx);
	}
	t[v]=merge(t[2*v],t[2*v+1]);
    }
}
 
 
void build(int v, int tl, int tr) {
    if (tl==tr) {
	if (tl>1) {
	    t[v]=node(a[tl]-a[tl-1]);
	} else {
	    t[v]=node();
	}
    } else {
	int tm = (tl+tr)/2;
	build(2*v,tl,tm);
	build(2*v+1,tm+1,tr);
	t[v]=merge(t[2*v],t[2*v+1]);
    }
}
 
 
void update(int l, int r, ll dx) {
    if (l>1) {
	upd(1,1,n,l,dx);
    }
    if (r<n) {
	upd(1,1,n,r+1,-dx);
    }
 
}
 
ll solve() {
    ll res = 0;
    for (int i=0; i<2; i++) {
	for (int j=0; j<2; j++) {
	    res = max(res, t[1].dp[i][j]);
	}
    }
    return res;
}
 
int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);  cout.tie(0);
 
    cin>>n>>q;
    for (int i=1; i<=n; i++) {
	cin>>a[i];
    }
 
    build(1,1,n);
    //watch(solve());
 
    while (q--) {
	int l,r,dx;
	cin>>l>>r>>dx;
	update(l,r,dx);
	cout<<solve()<<"\n";
    }
    
    
    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 40 / 40
• Subtask 3: 55 / 55