Submission #491895

#	Time	Username	Problem	Language	Result	Execution time	Memory
491895		ValiAntonie	Fancy Fence (CEOI20_fancyfence)	C++14	27 / 100	27 ms	3480 KiB

fancyfence

#include <bits/stdc++.h>
#define mod 1000000007
using namespace std;

stack <pair<int,int>> S;
int n,v[100005],i,dr[100005],st[100005],x,j,val,Max[100005],mark[100005],nr;
unsigned long long suma[100001],total;
pair <int,int > sor[100005];



long long bin(long long x){
	x %= mod;
    return ((x*(x+1)) / 2) % mod;
}
long long rectCount(long long x, long long y){
    return (bin(x)*bin(y))%mod;
}


int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin>>n;
for(i=1;i<=n;i++){
    cin>>v[i];
    if(v[i] == v[i-1])
        nr++;
    sor[i].first = v[i];
    sor[i].second = i;
    dr[i] = n + 1;
}
sort(sor+1,sor+n+1);
for(i=1;i<=n;i++){
    cin>>x;
    suma[i] = suma[i-1] % mod + x;
}
for(i=1;i<=n;i++){
    x = v[i];
    while(S.empty() == false && x<S.top().first){
        dr[S.top().second] = i;
        S.pop();
    }
    S.push({x,i});
}
while(S.empty() == false){
    S.pop();
}
for(i=n;i>=1;i--){
    x = v[i];
    while(S.empty() == false && x < S.top().first){
        st[S.top().second] = i;
        S.pop();
    }
    S.push({x,i});
}
for(i=1;i<=n;i++){
    mark[st[sor[i].second]] = sor[i].first;
    mark[dr[sor[i].second]] = sor[i].first;
}
if(nr + 1 != n){
//brut
for(i=1;i<=n;i++){
    total += rectCount((suma[dr[sor[i].second]-1] - suma[st[sor[i].second]]) % mod,sor[i].first % mod) % mod;
    total -= rectCount((suma[dr[sor[i].second]-1] - suma[st[sor[i].second]]) % mod,Max[sor[i].second] % mod) % mod;
    for(j=st[sor[i].second];j<=dr[sor[i].second];j++){
        Max[j] = sor[i].first;
    }
}
}
else{
    //subtask 4
    total = rectCount(suma[n],v[1]);
}
cout << total % mod;
return 0;
}

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