Submission #527384

#	Time	Username	Problem	Language	Result	Execution time	Memory
527384		idas	Fancy Fence (CEOI20_fancyfence)	C++11	43 / 100	139 ms	15116 KiB

fancyfence

#include <bits/stdc++.h>
#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr)
#define FOR(i, begin, end) for(int i = (begin); i < (end); i++)
#define TSTS int ttt; cin >> ttt; while(ttt--) solve()
#define all(x) (x).begin(), (x).end()
#define le(vec) vec[vec.size()-1]
#define sz(x) ((int)((x).size()))
#define pb push_back
#define s second
#define f first

using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef map<int, int> mii;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long double, long double> pdd;

const int INF=1e9, MOD=1e9+7, mod=998244353;
const ll LINF=1e18;

void setIO()
{
    FAST_IO;
}

void setIO(string s)
{
    FAST_IO;
    freopen((s+".in").c_str(), "r", stdin);
    freopen((s+".out").c_str(), "w", stdout);
}

const int N=1e5+10;
int n;
ll h[N], w[N];

ll calc(ll hh, ll L, ll wd)
{
    return ((2*hh-L+1)*L/2%MOD)*((wd+1)*wd/2%MOD)%MOD;
}

int main()
{
    setIO();
    cin >> n;
    FOR(i, 0, n) cin >> h[i];
    FOR(i, 0, n) cin >> w[i];

    ll lst=h[0], tot=0;
    vi nh, nw;
    FOR(i, 0, n)
    {
        if(h[i]==lst){
            tot+=w[i];
            tot%=MOD;
        }
        else{
            nh.pb(lst);
            nw.pb(tot);
            lst=h[i];
            tot=w[i];
        }
    }
    nh.pb(lst);
    nw.pb(tot);

    n=sz(nh);
    FOR(i, 0, n)
    {
        h[i]=nh[i];
        w[i]=nw[i];
    }

    set<int> pin, nin;
    FOR(i, 0, n)
    {
        pin.insert(i);
        nin.insert(-i);
    }

    queue<int> q;
    vector<pii> hgts;
    FOR(i, 0, n)
    {
        hgts.pb({h[i],i});
    }
    sort(all(hgts), greater<pii>());
    FOR(i, 0, n)
    {
        q.push(hgts[i].s);
    }

    ll ans=0;
    while(!q.empty()){
        int i=q.front(); q.pop();
        //cout << i << endl;
        if(!pin.count(i)) continue;
        int l=-*nin.upper_bound(-i), r=*pin.upper_bound(i);
        bool canL=nin.upper_bound(-i)!=nin.end(), canR=pin.upper_bound(i)!=pin.end();
        if(!canL && !canR) continue;
        else if(canR){
            if(h[r]>h[i]) continue;
            ll dif=h[i]-h[r];
            pin.erase(r);
            nin.erase(-r);

            ans+=calc(h[i], dif, w[i]);
            ans%=MOD;

            w[i]+=w[r]; w[i]%=MOD;
            h[i]=h[r];
        }
        else if(canL){
            if(h[l]>h[i]) continue;
            ll dif=h[i]-h[l];
            pin.erase(l);
            nin.erase(-l);

            ans+=calc(h[i], dif, w[i]);
            ans%=MOD;

            w[i]+=w[l]; w[i]%=MOD;
            h[i]=h[l];
        }
        else{
            if(h[l]>h[i]||h[r]>h[i]) continue;
            if(h[l]>h[r]){
                ll dif=h[i]-h[l];
                pin.erase(l);
                nin.erase(-l);

                ans+=calc(h[i], dif, w[i]);
                ans%=MOD;

                w[i]+=w[l]; w[i]%=MOD;
                h[i]=h[l];
            }
            else if(h[r]>h[l]){
                ll dif=h[i]-h[r];
                pin.erase(r);
                pin.erase(-r);

                ans+=calc(h[i], dif, w[i]);
                ans%=MOD;

                w[i]+=w[r]; w[i]%=MOD;
                h[i]=h[r];
            }
            else{
                ll dif=h[i]-h[l];
                pin.erase(l); pin.erase(r);
                nin.erase(-l); nin.erase(-r);

                ans+=calc(h[i], dif, w[i]);

                w[i]+=w[r]; w[i]%=MOD;
                w[i]+=w[l]; w[i]%=MOD;
                h[i]=h[l];
            }
        }
        q.push(i);
    }
    int in=*pin.begin();

    ans+=((h[in]+1)*h[in]/2%MOD)*((w[in]+1)*w[in]/2%MOD)%MOD;
    ans%=MOD;

    cout << ans;
}

Compilation message (stderr)

fancyfence.cpp: In function 'void setIO(std::string)':
fancyfence.cpp:32:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |     freopen((s+".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fancyfence.cpp:33:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     freopen((s+".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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