Submission #707612

#TimeUsernameProblemLanguageResultExecution timeMemory
707612emptypringlescanBigger segments (IZhO19_segments)C++17
13 / 100
2 ms468 KiB
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct node {
    int s, e;
    ll mn, mx, sum;
    bool lset;
    ll add_val, set_val;
    node *l, *r;
    node (int _s, int _e, int A[] = NULL): s(_s), e(_e), mn(0), mx(0), sum(0), lset(0), add_val(0), set_val(0), l(NULL), r(NULL) {
        if (A == NULL) return;
        if (s == e) mn = mx = sum = A[s];
        else {
            l = new node(s, (s+e)>>1, A), r = new node((s+e+2)>>1, e, A);
            combine();
        }
    }
    void create_children() {
        if (s == e) return;
        if (l != NULL) return;
        int m = (s+e)>>1;
        l = new node(s, m);
        r = new node(m+1, e);
    }
    void self_set(ll v) {
        lset = 1;
        mn = mx = set_val = v;
        sum = v * (e-s+1);
        add_val = 0;
    }
    void self_add(ll v) {
        if (lset) { self_set(v + set_val); return; }
        mn += v, mx += v, add_val += v;
        sum += v*(e-s+1);
    }
    void lazy_propagate() {
        if (s == e) return;
        if (lset) {
            l->self_set(set_val), r->self_set(set_val);
            lset = set_val = 0;
        }   
        if (add_val != 0) {
            l->self_add(add_val), r->self_add(add_val);
            add_val = 0;
        }
    }
    void combine() {
        if (l == NULL) return;
        sum = l->sum + r->sum;
        mn = min(l->mn, r->mn);
        mx = max(l->mx, r->mx);
    }
    void add(int x, int y, ll v) {
        if (s == x && e == y) { self_add(v); return; }
        int m = (s+e)>>1;
        create_children(); lazy_propagate();
        if (x <= m) l->add(x, min(y, m), v);
        if (y > m) r->add(max(x, m+1), y, v);
        combine();
    }
    void set(int x, int y, ll v) {
        if (s == x && e == y) { self_set(v); return; }
        int m = (s+e)>>1;
        create_children(); lazy_propagate();
        if (x <= m) l->set(x, min(y, m), v);
        if (y > m) r->set(max(x, m+1), y, v);
        combine();
    }
    ll range_sum(int x, int y) {
        if (s == x && e == y) return sum;
        if (l == NULL || lset) return (sum / (e-s+1)) * (y-x+1);
        int m = (s+e)>>1;
        lazy_propagate();
        if (y <= m) return l->range_sum(x, y);
        if (x > m) return r->range_sum(x, y);
        return l->range_sum(x, m) + r->range_sum(m+1, y);
    }
    ll range_min(int x, int y) {
        if (s == x && e == y) return mn;
        if (l == NULL || lset) return mn;
        int m = (s+e)>>1;
        lazy_propagate();
        if (y <= m) return l->range_min(x, y);
        if (x > m) return r->range_min(x, y);
        return min(l->range_min(x, m), r->range_min(m+1, y));
    }
    ll range_max(int x, int y) {
        if (s == x && e == y) return mx;
        if (l == NULL || lset) return mx;
        int m = (s+e)>>1;
        lazy_propagate();
        if (y <= m) return l->range_max(x, y);
        if (x > m) return r->range_max(x, y);
        return max(l->range_max(x, m), r->range_max(m+1, y));
    }
    ~node() {
        if (l != NULL) delete l;
        if (r != NULL) delete r;
    }
} *root;
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n;
	cin >> n;
	long long arr[n],pref[n+1];
	for(int i=0; i<n; i++) cin >> arr[i];
	pref[0]=0;
	for(int i=0; i<n; i++){
		pref[i+1]=pref[i]+arr[i];
	}
	pair<int,long long> dp[n+1];
	dp[0]={0,0};
	root=new node(0,1000005);
	
	for(int i=1; i<=n; i++){
		int lo=0,hi=i-1,mid;
		while(lo<hi){
			mid=(lo+hi+1LL)/2;
			int x=root->range_min(mid,i-1);
			if(x<=pref[i]) lo=mid;
			else hi=mid-1;
		}
		int x=lo;
      assert(pref[i]-pref[x]>=dp[x].second);
		dp[i]={dp[x].first+1LL,pref[i]-pref[x]};
		root->set(i,i,dp[i].second+pref[i]);
 
	}
	cout << dp[n].first;
	return 0;
}

Compilation message (stderr)

segments.cpp: In member function 'void node::lazy_propagate()':
segments.cpp:40:28: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   40 |             lset = set_val = 0;
      |                    ~~~~~~~~^~~
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