Submission #394952

#	Time	Username	Problem	Language	Result	Execution time	Memory
394952		Pichon5	Fancy Fence (CEOI20_fancyfence)	C++17	15 / 100	90 ms	4428 KiB

fancyfence

#include<bits/stdc++.h>
#define lcm(a,b) (a/__gcd(a,b))*b
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ll long long int
#define vi vector<int>
#define vll vector<ll>
#define pb push_back
#define F first
#define S second
#define mp make_pair
//salida rapida "\n"
//DECIMALES fixed<<sp(n)<<x<<endl;
//gcd(a,b)= ax + by
//lCB x&-x
//set.erase(it) - ersases the element present at the required index//auto it = s.find(element)
//set.find(element) - iterator pointing to the given element if it is present else return pointer pointing to set.end()
//set.lower_bound(element) - iterator pointing to element greater than or equal to the given element
//set.upper_bound(element) - iterator pointing to element greater than the given element
// | ^
//__builtin_popcount(x)
using namespace std;
const ll MOD=1e9+7;
vll h,w;
ll bin(ll x){
    return ((x*(x+1))/2)%MOD;
}
ll T(ll x,ll y){
    return (bin(x)%MOD*bin(y)%MOD)%MOD;
}
int main()
{ 
    int n,x;
    cin>>n;
    ll y;
    for(int i=0;i<n;i++){
        cin>>x;
        y=x;
        h.pb(x);
    }
    ll sum=0;
    for(int i=0;i<n;i++){
        cin>>x;
        sum+=x;
        sum%=MOD;
        w.pb(x);
    }
    ll res=0;
    cout<<T(sum,y)<<endl;
    /*for(int i=0;i<n;i++){
        ll Hmin=h[i];
        res+=T(h[i],w[i]);
        res%=MOD;
        for(int l=i+1;l<n;l++){
            Hmin=min(Hmin,h[l]);
            res+=T(Hmin,w[i]+w[l]);res%=MOD;
            res-=T(Hmin,w[i]);
            res-=T(Hmin,w[l]);
        }
    }*/
    //cout<<res<<endl;

    
    return 0;
}

Compilation message (stderr)

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:47:8: warning: unused variable 'res' [-Wunused-variable]
   47 |     ll res=0;
      |        ^~~
fancyfence.cpp:25:15: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   25 |     return ((x*(x+1))/2)%MOD;
      |             ~~^~~~~~~
fancyfence.cpp:34:8: note: 'y' was declared here
   34 |     ll y;
      |        ^

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