Submission #745905

#	Time	Username	Problem	Language	Result	Execution time	Memory
745905		vjudge1	Fancy Fence (CEOI20_fancyfence)	C++17	0 / 100	1 ms	256 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr ll MOD = 1e9 + 7;

ll mul(ll a, ll b){
    a %= MOD;
    b %= MOD;
    return ((a * b) % MOD);
}

ll half(ll a){
    return a % 2 ? a : a / 2;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    int h, w;
    for (int i=0; i<n; i++){
        cin >> h;
    }
    for (int i=0; i<n; i++){
        int a;
        cin >> a;
        w += a;
    }
    cout << mul(mul(half(h), half(h+1)), mul(half(w), half(w+1)));
}

Compilation message (stderr)

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:31:61: warning: 'w' may be used uninitialized in this function [-Wmaybe-uninitialized]
   31 |     cout << mul(mul(half(h), half(h+1)), mul(half(w), half(w+1)));
      |                                                            ~^~

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