Submission #379394

#	Time	Username	Problem	Language	Result	Execution time	Memory
379394		limabeans	Sjeckanje (COCI21_sjeckanje)	C++17	55 / 110	2072 ms	164608 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 dx;
    map<pair<int,int>,ll> dp;
    node() {
	dx = 0;
	dp[{sgn(0),sgn(0)}] = abs(0);
    }
    node(ll x) {
	dx = x;
	dp[{sgn(0),sgn(0)}] = abs(0);
	dp[{sgn(x),sgn(x)}] = abs(x);
    }
};


bool mergable(pair<int,int> p, pair<int,int> q) {
    return p.second*q.first >= 0;
}

node merge(node x, node y) {
    node res = x;
    for (auto p: y.dp) {
	res.dp[p.first] = max(res.dp[p.first], p.second);
    }
    for (auto p: x.dp) {
	for (auto q: y.dp) {
	    if (mergable(p.first,q.first)) {
		pair<int,int> ends = {p.first.first,q.first.second};
		res.dp[ends] = max(res.dp[ends], p.second+q.second);
	    }
	}
    }
    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].dx;
	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]);
    }
}

node qry(int v, int tl, int tr, int l, int r) {
    assert(0);
    if (l>tr || r<tl) {
	return node();
    } else if (l<=tl && tr<=r) {
	return t[v];
    } else {
	int tm = (tl+tr)/2;
	return merge(qry(2*v,tl,tm,l,r),qry(2*v+1,tm+1,tr,l,r));
    }
}

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 (auto p: t[1].dp) {
	res = max(res, p.second);
    }
    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);

    while (q--) {
	int l,r,dx;
	cin>>l>>r>>dx;
	update(l,r,dx);
	cout<<solve()<<"\n";
    }
    
    
    return 0;
}

/*
ll solve() {
    ll dp0 = 0;
    ll dp1 = 0;
    
    ll diff0 = 0;
    for (int i=2; i<=n; i++) {
	ll diff = a[i]-a[i-1];
	if (diff0*diff>=0) {
	    ll _dp0 = max(dp0,dp1);
	    ll _dp1 = max(dp1,dp0)+abs(diff);
	    dp0 = _dp0;
	    dp1 = _dp1;
	} else {
	    ll _dp0 = max(dp0,dp1);
	    ll _dp1 = dp0+abs(diff);
	    dp0 = _dp0;
	    dp1 = _dp1;
	}
	diff0 = diff;
    }
    return max(dp0, dp1);
}
*/

• Subtask 1: 15 / 15
• Subtask 2: 40 / 40
• Subtask 3: 0 / 55