Submission #44113287

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Source Code Expand

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define xx first
#define yy second
#define ff(i,s,f) for(int i=s;i<f;i++)
#define fb(i,s,f) for(int i=(s)-1;i>=f;i--)
#define ffi(i,s,f) for(int i=s;i<=f;i++)
#define fbi(i,s,f) for(int i=s;i>=f;i--)
#define srt(a) sort(a.begin(),a.end());
#define srtg(a,int) sort(a.begin(),a.end(),greater<int>())
#define lb(a,x) lower_bound(a.begin(),a.end(),x)
#define ub(a,x) upper_bound(a.begin(),a.end(),x)
#define fnd(a,x) find(a.begin(),a.end(),x)
#define ios ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef string str;

const int maxn=5e5+10;
const int inf=1e9;

int n;
int a[maxn];
int smoze[4*maxn];
int lazy[4*maxn];
int dokle[4*maxn];

void build(int ind=1,int l=0,int r=n-1){
    if(l==r){
        smoze[ind]=1;
        return;
    }
    int mid=l+(r-l)/2;
    build(2*ind,l,mid);
    build(2*ind+1,mid+1,r);
    smoze[ind]=smoze[2*ind]+smoze[2*ind+1];
}

void push(int ind){
    if(lazy[ind]==0) return;
    smoze[2*ind]=0;
    smoze[2*ind+1]=0;
    lazy[2*ind]=1;
    lazy[2*ind+1]=1;
    lazy[ind]=0;
}

void ubi(int tl,int tr,int ind=1,int l=0,int r=n-1){
    if(tl>tr) return;
    if(l!=r) push(ind);
    if(tl<=l && r<=tr){
        smoze[ind]=0;
        lazy[ind]=1;
        return;
    }
    int mid=l+(r-l)/2;
    if(tl<=mid) ubi(tl,tr,2*ind,l,mid);
    if(tr>mid) ubi(tl,tr,2*ind+1,mid+1,r);
    smoze[ind]=smoze[2*ind]+smoze[2*ind+1];
}

void update(int t,int v,int ind=1,int l=0,int r=n-1){
    if(l==r){
        dokle[ind]=v;
        return;
    }
    int mid=l+(r-l)/2;
    if(t<=mid) update(t,v,2*ind,l,mid);
    else update(t,v,2*ind+1,mid+1,r);
    dokle[ind]=min(dokle[2*ind],dokle[2*ind+1]);
}

int mini(int tl,int tr,int ind=1,int l=0,int r=n-1){
    if(tl>tr) return inf;
    if(tl<=l && r<=tr) return dokle[ind];
    int mid=l+(r-l)/2;
    int ret=inf;
    if(tl<=mid) ret=min(ret,mini(tl,tr,2*ind,l,mid));
    if(tr>mid) ret=min(ret,mini(tl,tr,2*ind+1,mid+1,r));
    return ret;
}

int moze(int tl,int tr,int ind=1,int l=0,int r=n-1){
    if(tl>tr) return 0;
    if(tl<=l && r<=tr) return smoze[ind];
    int mid=l+(r-l)/2;
    int ret=0;
    if(tl<=mid) ret+=moze(tl,tr,2*ind,l,mid);
    if(tr>mid) ret+=moze(tl,tr,2*ind+1,mid+1,r);
    return ret;
}

void solve(){
    cin>>n;
    for(int i=0;i<n;i++) cin>>a[i];
    stack<pair<int,int> > stek;
    ll res=0;
    build();
    for(int i=0;i<n;i++){
        while(a[i]!=1 && !stek.empty() && stek.top().first!=a[i]-1){
            stek.pop();
        }
        if(a[i]==1){
            stek.push({1,i});
            update(i,i);
        }else{
            if(stek.empty()){
                update(i,-1);
            }else{
                auto tmp=stek.top();
                update(i,mini(stek.top().second,i-1));
                stek.pop();
                stek.push({tmp.first+1,tmp.second});
            }
        }
        ubi(mini(i,i)+1,i);
        res+=moze(0,i);
    }
    cout<<res;
}

int main(){
    ios;
    int t=1;
    //cin>>t;
    while(t--) solve();
    return 0;
}

Submission Info

Judge Result