Submission #534912

#	Time	Username	Problem	Language	Result	Execution time	Memory
534912		vector	Fancy Fence (CEOI20_fancyfence)	C++17	100 / 100	155 ms	38272 KiB

fancyfence

#include<bits/stdc++.h>
#define MOD 1000000007
#define SIZE 100010
using namespace std;
typedef long long ll;
struct st1
{
    ll l,r;
};
struct st2
{
    ll h,w,idx;
};
ll N,psum[SIZE],ans,seg2[SIZE<<2],lz[SIZE<<2];
st1 sparse[SIZE][17];
st2 A[SIZE];
vector<st2>v;
void push(ll l,ll r,ll node)
{
    if(lz[node]==0)return;
    seg2[node]=lz[node];
    if(l^r)lz[node<<1]=lz[node<<1|1]=lz[node];
    lz[node]=0;
}
void upd(ll l,ll r,ll node,ll s,ll e,ll x)
{
    push(l,r,node);
    if(l>e||r<s)return;
    if(s<=l&&r<=e){
        lz[node]=x;
        push(l,r,node);
        return;
    }
    ll mid=l+r>>1;
    upd(l,mid,node<<1,s,e,x);
    upd(mid+1,r,node<<1|1,s,e,x);
}
ll que(ll l,ll r,ll node,ll s)
{
    push(l,r,node);
    if(l>s||r<s)return 0;
    if(l==s&&r==s)return seg2[node];
    ll mid=l+r>>1;
    return max(que(l,mid,node<<1,s),que(mid+1,r,node<<1|1,s));
}
bool comp(st2 x,st2 y)
{
    return x.h<y.h;
}
ll S(ll x)
{
    x%=MOD;
    return (x*(x+1)/2)%MOD;
}
int main()
{
    ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    cin>>N;
    for(int i=1;i<=N;i++)cin>>A[i].h;
    for(int i=1;i<=N;i++)cin>>A[i].w;
    bool f=false;
    st2 temp={0,0,0};
    v.push_back(temp);
    for(int i=1;i<=N;i++){
        if(f){
            if(temp.h==A[i].h)temp.w+=A[i].w;
            else{
                v.push_back(temp);
                f=false;
            }
        }
        if(!f){
            temp.h=A[i].h;
            temp.w=A[i].w;
            f=true;
        }
    }
    v.push_back(temp);
    N=v.size()-1;
    temp={0,MOD,N+1};
    v.push_back(temp);
    for(ll i=1;i<=N;i++){
        v[i].idx=i;
        //printf("[%lld %lld %lld]\n",v[i].h,v[i].w,v[i].idx);
        psum[i]=psum[i-1]+v[i].w;
    }
    for(ll i=1;i<=N;i++){
        sparse[i][0].r=v[i+1].h;
        sparse[i][0].l=v[i-1].h;
        //printf("[%lld %lld] ",sparse[i][0].l,sparse[i][0].r);
    }
    //printf("\n");
    for(ll j=1;j<17;j++){
        for(ll i=1;i<=N;i++){
            sparse[i][j].r=min(sparse[i][j-1].r,sparse[min(N,i+(1<<(j-1)))][j-1].r);
            sparse[i][j].l=min(sparse[i][j-1].l,sparse[max(1ll,i-(1<<(j-1)))][j-1].l);
            //printf("[%lld %lld] ",sparse[i][j].l,sparse[i][j].r);
        }
        //printf("\n");
    }
    sort(v.begin(),v.end()-1,comp);
    for(ll j=1;j<=N;j++){
        ll i=v[j].idx;
        ll l=1,r=i,mid,a,b,mx,x=i;
        for(ll k=16;k>=0;k--)if(sparse[x][k].r>=v[j].h)x=min(N,x+(1<<k));
        b=x;
        x=i;
        for(ll k=16;k>=0;k--)if(sparse[x][k].l>=v[j].h)x=max(1ll,x-(1<<k));
        a=x;
        mx=que(1,N,1,i);
        upd(1,N,1,a,b,v[j].h);
        //printf("%lld %lld %lld %lld %lld\n",a,b,i,v[j].h,mx);
        ans=(ans+S(psum[b]-psum[a-1])*(S(v[j].h)-S(mx)+MOD))%MOD;
        //printf("%lld\n",ans);
    }
    cout<<ans;
}

Compilation message (stderr)

fancyfence.cpp: In function 'void upd(ll, ll, ll, ll, ll, ll)':
fancyfence.cpp:34:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   34 |     ll mid=l+r>>1;
      |            ~^~
fancyfence.cpp: In function 'll que(ll, ll, ll, ll)':
fancyfence.cpp:43:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   43 |     ll mid=l+r>>1;
      |            ~^~
fancyfence.cpp: In function 'int main()':
fancyfence.cpp:104:12: warning: unused variable 'l' [-Wunused-variable]
  104 |         ll l=1,r=i,mid,a,b,mx,x=i;
      |            ^
fancyfence.cpp:104:16: warning: unused variable 'r' [-Wunused-variable]
  104 |         ll l=1,r=i,mid,a,b,mx,x=i;
      |                ^
fancyfence.cpp:104:20: warning: unused variable 'mid' [-Wunused-variable]
  104 |         ll l=1,r=i,mid,a,b,mx,x=i;
      |                    ^~~

• Subtask 1: 0 / 0
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 18 / 18
• Subtask 7: 27 / 27